diff --git a/esphome/automation.py b/esphome/automation.py
index 2439b1ddc4..d9b8b2ec57 100644
--- a/esphome/automation.py
+++ b/esphome/automation.py
@@ -57,8 +57,23 @@ def maybe_conf(conf, *validators):
     return validate
 
 
-def register_action(name: str, action_type: MockObjClass, schema: cv.Schema):
-    return ACTION_REGISTRY.register(name, action_type, schema)
+def register_action(
+    name: str,
+    action_type: MockObjClass,
+    schema: cv.Schema,
+    *,
+    synchronous: bool = False,
+):
+    """Register an action type.
+
+    Actions default to ``synchronous=False`` (safe default), meaning string
+    arguments use owning std::string to prevent dangling references.
+
+    Set ``synchronous=True`` only for actions that complete synchronously
+    and never store trigger arguments for later execution.  This allows
+    the code generator to use non-owning StringRef for zero-copy access.
+    """
+    return ACTION_REGISTRY.register(name, action_type, schema, synchronous=synchronous)
 
 
 def register_condition(name: str, condition_type: MockObjClass, schema: cv.Schema):
@@ -335,7 +350,9 @@ async def component_is_idle_condition_to_code(
 
 
 @register_action(
-    "delay", DelayAction, cv.templatable(cv.positive_time_period_milliseconds)
+    "delay",
+    DelayAction,
+    cv.templatable(cv.positive_time_period_milliseconds),
 )
 async def delay_action_to_code(
     config: ConfigType,
@@ -366,6 +383,7 @@ async def delay_action_to_code(
         cv.has_at_least_one_key(CONF_THEN, CONF_ELSE),
         cv.has_at_least_one_key(CONF_CONDITION, CONF_ANY, CONF_ALL),
     ),
+    synchronous=True,
 )
 async def if_action_to_code(
     config: ConfigType,
@@ -394,6 +412,7 @@ async def if_action_to_code(
             cv.Required(CONF_THEN): validate_action_list,
         }
     ),
+    synchronous=True,
 )
 async def while_action_to_code(
     config: ConfigType,
@@ -417,6 +436,7 @@ async def while_action_to_code(
             cv.Required(CONF_THEN): validate_action_list,
         }
     ),
+    synchronous=True,
 )
 async def repeat_action_to_code(
     config: ConfigType,
@@ -461,7 +481,12 @@ async def wait_until_action_to_code(
     return var
 
 
-@register_action("lambda", LambdaAction, cv.lambda_)
+# Lambda executes user C++ inline and returns — synchronous by execution model.
+# User code could theoretically store the StringRef for deferred use, but StringRef
+# is a view type and storing views beyond their scope is always unsafe regardless
+# of this optimization.  Marking non-synchronous would disable StringRef for nearly
+# all user services since most use lambda.
+@register_action("lambda", LambdaAction, cv.lambda_, synchronous=True)
 async def lambda_action_to_code(
     config: ConfigType,
     action_id: ID,
@@ -480,6 +505,7 @@ async def lambda_action_to_code(
             cv.Required(CONF_ID): cv.use_id(cg.PollingComponent),
         }
     ),
+    synchronous=True,
 )
 async def component_update_action_to_code(
     config: ConfigType,
@@ -499,6 +525,7 @@ async def component_update_action_to_code(
             cv.Required(CONF_ID): cv.use_id(cg.PollingComponent),
         }
     ),
+    synchronous=True,
 )
 async def component_suspend_action_to_code(
     config: ConfigType,
@@ -521,6 +548,7 @@ async def component_suspend_action_to_code(
             ),
         }
     ),
+    synchronous=True,
 )
 async def component_resume_action_to_code(
     config: ConfigType,
@@ -578,6 +606,27 @@ async def build_condition_list(
     return conditions
 
 
+def has_non_synchronous_actions(actions: ConfigType) -> bool:
+    """Check if a validated action list contains any non-synchronous actions.
+
+    Non-synchronous actions (delay, wait_until, script.wait, etc.) store
+    trigger args for later execution, making non-owning types like StringRef
+    unsafe.  Actions that haven't been audited default to non-synchronous.
+    """
+    if isinstance(actions, list):
+        return any(has_non_synchronous_actions(item) for item in actions)
+    if isinstance(actions, dict):
+        for key in actions:
+            if key in ACTION_REGISTRY and not ACTION_REGISTRY[key].synchronous:
+                return True
+        return any(
+            has_non_synchronous_actions(v)
+            for v in actions.values()
+            if isinstance(v, (list, dict))
+        )
+    return False
+
+
 async def build_automation(
     trigger: MockObj, args: TemplateArgsType, config: ConfigType
 ) -> MockObj:
diff --git a/esphome/components/api/__init__.py b/esphome/components/api/__init__.py
index 3f7cafb485..d7b6bec357 100644
--- a/esphome/components/api/__init__.py
+++ b/esphome/components/api/__init__.py
@@ -76,7 +76,7 @@ SERVICE_ARG_NATIVE_TYPES: dict[str, MockObj] = {
     "bool": cg.bool_,
     "int": cg.int32,
     "float": cg.float_,
-    "string": cg.std_string,
+    "string": cg.StringRef,
     "bool[]": cg.FixedVector.template(cg.bool_).operator("const").operator("ref"),
     "int[]": cg.FixedVector.template(cg.int32).operator("const").operator("ref"),
     "float[]": cg.FixedVector.template(cg.float_).operator("const").operator("ref"),
@@ -380,9 +380,18 @@ async def to_code(config: ConfigType) -> None:
                 if is_optional:
                     func_args.append((cg.bool_, "return_response"))
 
+            # Check if action chain has non-synchronous actions that would make
+            # non-owning StringRef dangle (rx_buf_ reused after delay)
+            has_non_synchronous = automation.has_non_synchronous_actions(
+                conf.get(CONF_THEN, [])
+            )
+
             service_arg_names: list[str] = []
             for name, var_ in conf[CONF_VARIABLES].items():
                 native = SERVICE_ARG_NATIVE_TYPES[var_]
+                # Fall back to std::string for string args if non-synchronous actions exist
+                if has_non_synchronous and native is cg.StringRef:
+                    native = cg.std_string
                 service_template_args.append(native)
                 func_args.append((native, name))
                 service_arg_names.append(name)
@@ -509,11 +518,13 @@ HOMEASSISTANT_ACTION_ACTION_SCHEMA = cv.All(
     "homeassistant.action",
     HomeAssistantServiceCallAction,
     HOMEASSISTANT_ACTION_ACTION_SCHEMA,
+    synchronous=True,
 )
 @automation.register_action(
     "homeassistant.service",
     HomeAssistantServiceCallAction,
     HOMEASSISTANT_ACTION_ACTION_SCHEMA,
+    synchronous=True,
 )
 async def homeassistant_service_to_code(
     config: ConfigType,
@@ -604,6 +615,7 @@ HOMEASSISTANT_EVENT_ACTION_SCHEMA = cv.Schema(
     "homeassistant.event",
     HomeAssistantServiceCallAction,
     HOMEASSISTANT_EVENT_ACTION_SCHEMA,
+    synchronous=True,
 )
 async def homeassistant_event_to_code(config, action_id, template_arg, args):
     cg.add_define("USE_API_HOMEASSISTANT_SERVICES")
@@ -644,6 +656,7 @@ HOMEASSISTANT_TAG_SCANNED_ACTION_SCHEMA = cv.maybe_simple_value(
     "homeassistant.tag_scanned",
     HomeAssistantServiceCallAction,
     HOMEASSISTANT_TAG_SCANNED_ACTION_SCHEMA,
+    synchronous=True,
 )
 async def homeassistant_tag_scanned_to_code(config, action_id, template_arg, args):
     cg.add_define("USE_API_HOMEASSISTANT_SERVICES")
diff --git a/esphome/components/api/api.proto b/esphome/components/api/api.proto
index d7f32cd8d1..802e3e3ae2 100644
--- a/esphome/components/api/api.proto
+++ b/esphome/components/api/api.proto
@@ -834,6 +834,33 @@ message GetTimeRequest {
   option (source) = SOURCE_SERVER;
 }
 
+enum DSTRuleType {
+  DST_RULE_TYPE_NONE = 0;
+  DST_RULE_TYPE_MONTH_WEEK_DAY = 1;
+  DST_RULE_TYPE_JULIAN_NO_LEAP = 2;
+  DST_RULE_TYPE_DAY_OF_YEAR = 3;
+}
+
+message DSTRule {
+  option (source) = SOURCE_CLIENT;
+
+  sint32 time_seconds = 1;
+  uint32 day = 2;
+  DSTRuleType type = 3;
+  uint32 month = 4;
+  uint32 week = 5;
+  uint32 day_of_week = 6;
+}
+
+message ParsedTimezone {
+  option (source) = SOURCE_CLIENT;
+
+  sint32 std_offset_seconds = 1;
+  sint32 dst_offset_seconds = 2;
+  DSTRule dst_start = 3;
+  DSTRule dst_end = 4;
+}
+
 message GetTimeResponse {
   option (id) = 37;
   option (source) = SOURCE_CLIENT;
@@ -841,6 +868,7 @@ message GetTimeResponse {
 
   fixed32 epoch_seconds = 1;
   string timezone = 2;
+  ParsedTimezone parsed_timezone = 3;
 }
 
 // ==================== USER-DEFINES SERVICES ====================
diff --git a/esphome/components/api/api_connection.cpp b/esphome/components/api/api_connection.cpp
index 9ee4c15308..738dd1ef05 100644
--- a/esphome/components/api/api_connection.cpp
+++ b/esphome/components/api/api_connection.cpp
@@ -242,24 +242,11 @@ void APIConnection::loop() {
     return;
   }
 
-  if (this->flags_.sent_ping) {
-    // Disconnect if not responded within 2.5*keepalive
-    if (now - this->last_traffic_ > KEEPALIVE_DISCONNECT_TIMEOUT) {
-      on_fatal_error();
-      this->log_client_(ESPHOME_LOG_LEVEL_WARN, LOG_STR("is unresponsive; disconnecting"));
-    }
-  } else if (now - this->last_traffic_ > KEEPALIVE_TIMEOUT_MS && !this->flags_.remove) {
-    // Only send ping if we're not disconnecting
-    ESP_LOGVV(TAG, "Sending keepalive PING");
-    PingRequest req;
-    this->flags_.sent_ping = this->send_message(req, PingRequest::MESSAGE_TYPE);
-    if (!this->flags_.sent_ping) {
-      // If we can't send the ping request directly (tx_buffer full),
-      // schedule it at the front of the batch so it will be sent with priority
-      ESP_LOGW(TAG, "Buffer full, ping queued");
-      this->schedule_message_front_(nullptr, PingRequest::MESSAGE_TYPE, PingRequest::ESTIMATED_SIZE);
-      this->flags_.sent_ping = true;  // Mark as sent to avoid scheduling multiple pings
-    }
+  // Keepalive: only call into the cold path when enough time has elapsed.
+  // When sent_ping is true, last_traffic_ hasn't been updated so this
+  // condition is already satisfied — covers both send-ping and disconnect cases.
+  if (now - this->last_traffic_ > KEEPALIVE_TIMEOUT_MS) {
+    this->check_keepalive_(now);
   }
 
 #ifdef USE_API_HOMEASSISTANT_STATES
@@ -275,6 +262,29 @@ void APIConnection::loop() {
 #endif
 }
 
+void APIConnection::check_keepalive_(uint32_t now) {
+  // Caller guarantees: now - last_traffic_ > KEEPALIVE_TIMEOUT_MS
+  if (this->flags_.sent_ping) {
+    // Disconnect if not responded within 2.5*keepalive
+    if (now - this->last_traffic_ > KEEPALIVE_DISCONNECT_TIMEOUT) {
+      on_fatal_error();
+      this->log_client_(ESPHOME_LOG_LEVEL_WARN, LOG_STR("is unresponsive; disconnecting"));
+    }
+  } else if (!this->flags_.remove) {
+    // Only send ping if we're not disconnecting
+    ESP_LOGVV(TAG, "Sending keepalive PING");
+    PingRequest req;
+    this->flags_.sent_ping = this->send_message(req, PingRequest::MESSAGE_TYPE);
+    if (!this->flags_.sent_ping) {
+      // If we can't send the ping request directly (tx_buffer full),
+      // schedule it at the front of the batch so it will be sent with priority
+      ESP_LOGW(TAG, "Buffer full, ping queued");
+      this->schedule_message_front_(nullptr, PingRequest::MESSAGE_TYPE, PingRequest::ESTIMATED_SIZE);
+      this->flags_.sent_ping = true;  // Mark as sent to avoid scheduling multiple pings
+    }
+  }
+}
+
 void APIConnection::process_active_iterator_() {
   // Caller ensures active_iterator_ != NONE
   if (this->active_iterator_ == ActiveIterator::LIST_ENTITIES) {
@@ -1113,7 +1123,30 @@ void APIConnection::on_get_time_response(const GetTimeResponse &value) {
     homeassistant::global_homeassistant_time->set_epoch_time(value.epoch_seconds);
 #ifdef USE_TIME_TIMEZONE
     if (!value.timezone.empty()) {
-      homeassistant::global_homeassistant_time->set_timezone(value.timezone.c_str(), value.timezone.size());
+      // Check if the sender provided pre-parsed timezone data.
+      // If std_offset is non-zero or DST rules are present, the parsed data was populated.
+      // For UTC (all zeros), string parsing produces the same result, so the fallback is equivalent.
+      const auto &pt = value.parsed_timezone;
+      if (pt.std_offset_seconds != 0 || pt.dst_start.type != enums::DST_RULE_TYPE_NONE) {
+        time::ParsedTimezone tz{};
+        tz.std_offset_seconds = pt.std_offset_seconds;
+        tz.dst_offset_seconds = pt.dst_offset_seconds;
+        tz.dst_start.time_seconds = pt.dst_start.time_seconds;
+        tz.dst_start.day = static_cast<uint16_t>(pt.dst_start.day);
+        tz.dst_start.type = static_cast<time::DSTRuleType>(pt.dst_start.type);
+        tz.dst_start.month = static_cast<uint8_t>(pt.dst_start.month);
+        tz.dst_start.week = static_cast<uint8_t>(pt.dst_start.week);
+        tz.dst_start.day_of_week = static_cast<uint8_t>(pt.dst_start.day_of_week);
+        tz.dst_end.time_seconds = pt.dst_end.time_seconds;
+        tz.dst_end.day = static_cast<uint16_t>(pt.dst_end.day);
+        tz.dst_end.type = static_cast<time::DSTRuleType>(pt.dst_end.type);
+        tz.dst_end.month = static_cast<uint8_t>(pt.dst_end.month);
+        tz.dst_end.week = static_cast<uint8_t>(pt.dst_end.week);
+        tz.dst_end.day_of_week = static_cast<uint8_t>(pt.dst_end.day_of_week);
+        time::set_global_tz(tz);
+      } else {
+        homeassistant::global_homeassistant_time->set_timezone(value.timezone.c_str(), value.timezone.size());
+      }
     }
 #endif
   }
@@ -1701,37 +1734,42 @@ void APIConnection::on_home_assistant_state_response(const HomeAssistantStateRes
     return;
   }
 
+  // Null-terminate state in-place for safe c_str() usage (e.g., parse_number in callbacks).
+  // Safe: decode is complete, byte after string data was already consumed during parse,
+  // and frame helpers reserve RX_BUF_NULL_TERMINATOR extra byte in rx_buf_.
+  // const_cast is safe: msg references mutable rx_buf_ data; the const& handler
+  // signature is a generated protobuf pattern, not a true immutability contract.
+  if (!msg.state.empty()) {
+    const_cast<char *>(msg.state.c_str())[msg.state.size()] = '\0';
+  }
+
   for (auto &it : this->parent_->get_state_subs()) {
-    // Compare entity_id: check length matches and content matches
-    size_t entity_id_len = strlen(it.entity_id);
-    if (entity_id_len != msg.entity_id.size() ||
-        memcmp(it.entity_id, msg.entity_id.c_str(), msg.entity_id.size()) != 0) {
+    if (msg.entity_id != it.entity_id) {
       continue;
     }
 
-    // Compare attribute: either both have matching attribute, or both have none
-    size_t sub_attr_len = it.attribute != nullptr ? strlen(it.attribute) : 0;
-    if (sub_attr_len != msg.attribute.size() ||
-        (sub_attr_len > 0 && memcmp(it.attribute, msg.attribute.c_str(), sub_attr_len) != 0)) {
+    // If subscriber has attribute filter (non-null), message attribute must match it;
+    // if subscriber has no filter (nullptr), message must have no attribute.
+    if (it.attribute != nullptr ? msg.attribute != it.attribute : !msg.attribute.empty()) {
       continue;
     }
 
-    // Create null-terminated state for callback (parse_number needs null-termination)
-    // HA state max length is 255 characters, but attributes can be much longer
-    // Use stack buffer for common case (states), heap fallback for large attributes
-    size_t state_len = msg.state.size();
-    SmallBufferWithHeapFallback<MAX_STATE_LEN + 1> state_buf_alloc(state_len + 1);
-    char *state_buf = reinterpret_cast<char *>(state_buf_alloc.get());
-    if (state_len > 0) {
-      memcpy(state_buf, msg.state.c_str(), state_len);
-    }
-    state_buf[state_len] = '\0';
-    it.callback(StringRef(state_buf, state_len));
+    it.callback(msg.state);
   }
 }
 #endif
 #ifdef USE_API_USER_DEFINED_ACTIONS
 void APIConnection::on_execute_service_request(const ExecuteServiceRequest &msg) {
+  // Null-terminate string args in-place for safe c_str() usage in YAML service triggers.
+  // Safe: full ExecuteServiceRequest decode is complete, all bytes in rx_buf_ consumed,
+  // and frame helpers reserve RX_BUF_NULL_TERMINATOR extra byte for the last field.
+  // const_cast is safe: msg references mutable rx_buf_ data; the const& handler
+  // signature is a generated protobuf pattern, not a true immutability contract.
+  for (auto &arg : const_cast<ExecuteServiceRequest &>(msg).args) {
+    if (!arg.string_.empty()) {
+      const_cast<char *>(arg.string_.c_str())[arg.string_.size()] = '\0';
+    }
+  }
   bool found = false;
 #ifdef USE_API_USER_DEFINED_ACTION_RESPONSES
   // Register the call and get a unique server-generated action_call_id
diff --git a/esphome/components/api/api_connection.h b/esphome/components/api/api_connection.h
index e34bed8ada..37855b2482 100644
--- a/esphome/components/api/api_connection.h
+++ b/esphome/components/api/api_connection.h
@@ -370,6 +370,10 @@ class APIConnection final : public APIServerConnectionBase {
     return this->client_supports_api_version(1, 14) ? MAX_INITIAL_PER_BATCH : MAX_INITIAL_PER_BATCH_LEGACY;
   }
 
+  // Send keepalive ping or disconnect unresponsive client.
+  // Cold path — extracted from loop() to reduce instruction cache pressure.
+  void __attribute__((noinline)) check_keepalive_(uint32_t now);
+
   // Process active iterator (list_entities/initial_state) during connection setup.
   // Extracted from loop() — only runs during initial handshake, NONE in steady state.
   void __attribute__((noinline)) process_active_iterator_();
diff --git a/esphome/components/api/api_frame_helper.h b/esphome/components/api/api_frame_helper.h
index 03f3814bb9..2b4e9ea3cd 100644
--- a/esphome/components/api/api_frame_helper.h
+++ b/esphome/components/api/api_frame_helper.h
@@ -29,6 +29,10 @@ static constexpr uint16_t MAX_MESSAGE_SIZE = 8192;  // 8 KiB for ESP8266
 static constexpr uint16_t MAX_MESSAGE_SIZE = 32768;  // 32 KiB for ESP32 and other platforms
 #endif
 
+// Extra byte reserved in rx_buf_ beyond the message size so protobuf
+// StringRef fields can be null-terminated in-place after decode.
+static constexpr uint16_t RX_BUF_NULL_TERMINATOR = 1;
+
 // Maximum number of messages to batch in a single write operation
 // Must be >= MAX_INITIAL_PER_BATCH in api_connection.h (enforced by static_assert there)
 static constexpr size_t MAX_MESSAGES_PER_BATCH = 34;
diff --git a/esphome/components/api/api_frame_helper_noise.cpp b/esphome/components/api/api_frame_helper_noise.cpp
index 2aad732f7f..3ae35e9be8 100644
--- a/esphome/components/api/api_frame_helper_noise.cpp
+++ b/esphome/components/api/api_frame_helper_noise.cpp
@@ -194,16 +194,21 @@ APIError APINoiseFrameHelper::try_read_frame_() {
   uint16_t msg_size = (((uint16_t) rx_header_buf_[1]) << 8) | rx_header_buf_[2];
 
   // Check against size limits to prevent OOM: MAX_HANDSHAKE_SIZE for handshake, MAX_MESSAGE_SIZE for data
-  uint16_t limit = (state_ == State::DATA) ? MAX_MESSAGE_SIZE : MAX_HANDSHAKE_SIZE;
+  bool is_data = (state_ == State::DATA);
+  uint16_t limit = is_data ? MAX_MESSAGE_SIZE : MAX_HANDSHAKE_SIZE;
   if (msg_size > limit) {
     state_ = State::FAILED;
     HELPER_LOG("Bad packet: message size %u exceeds maximum %u", msg_size, limit);
-    return (state_ == State::DATA) ? APIError::BAD_DATA_PACKET : APIError::BAD_HANDSHAKE_PACKET_LEN;
+    return is_data ? APIError::BAD_DATA_PACKET : APIError::BAD_HANDSHAKE_PACKET_LEN;
   }
 
-  // Reserve space for body
-  if (this->rx_buf_.size() != msg_size) {
-    this->rx_buf_.resize(msg_size);
+  // Reserve space for body (+ null terminator in DATA state so protobuf
+  // StringRef fields can be safely null-terminated in-place after decode.
+  // During handshake, rx_buf_.size() is used in prologue construction, so
+  // the buffer must be exactly msg_size to avoid prologue mismatch.)
+  uint16_t alloc_size = msg_size + (is_data ? RX_BUF_NULL_TERMINATOR : 0);
+  if (this->rx_buf_.size() != alloc_size) {
+    this->rx_buf_.resize(alloc_size);
   }
 
   if (rx_buf_len_ < msg_size) {
@@ -407,7 +412,18 @@ APIError APINoiseFrameHelper::read_packet(ReadPacketBuffer *buffer) {
 
   NoiseBuffer mbuf;
   noise_buffer_init(mbuf);
-  noise_buffer_set_inout(mbuf, this->rx_buf_.data(), this->rx_buf_.size(), this->rx_buf_.size());
+  // read_packet() must only be called in DATA state; the extra
+  // RX_BUF_NULL_TERMINATOR byte is only allocated in DATA state
+  // (see try_read_frame_), so calling this during handshake would
+  // underflow the size calculation below.
+#ifdef ESPHOME_DEBUG_API
+  assert(this->state_ == State::DATA);
+#endif
+  // rx_buf_ has RX_BUF_NULL_TERMINATOR extra byte for null termination
+  // (only added in DATA state — see try_read_frame_), so subtract it
+  // to get the actual encrypted data size for decryption.
+  size_t encrypted_size = this->rx_buf_.size() - RX_BUF_NULL_TERMINATOR;
+  noise_buffer_set_inout(mbuf, this->rx_buf_.data(), encrypted_size, encrypted_size);
   int err = noise_cipherstate_decrypt(this->recv_cipher_, &mbuf);
   APIError decrypt_err =
       handle_noise_error_(err, LOG_STR("noise_cipherstate_decrypt"), APIError::CIPHERSTATE_DECRYPT_FAILED);
@@ -574,7 +590,9 @@ APIError APINoiseFrameHelper::init_handshake_() {
 }
 
 APIError APINoiseFrameHelper::check_handshake_finished_() {
+#ifdef ESPHOME_DEBUG_API
   assert(state_ == State::HANDSHAKE);
+#endif
 
   int action = noise_handshakestate_get_action(handshake_);
   if (action == NOISE_ACTION_READ_MESSAGE || action == NOISE_ACTION_WRITE_MESSAGE)
diff --git a/esphome/components/api/api_frame_helper_plaintext.cpp b/esphome/components/api/api_frame_helper_plaintext.cpp
index 5069dbf68b..e2bb56e0ac 100644
--- a/esphome/components/api/api_frame_helper_plaintext.cpp
+++ b/esphome/components/api/api_frame_helper_plaintext.cpp
@@ -163,9 +163,10 @@ APIError APIPlaintextFrameHelper::try_read_frame_() {
   }
   // header reading done
 
-  // Reserve space for body
-  if (this->rx_buf_.size() != this->rx_header_parsed_len_) {
-    this->rx_buf_.resize(this->rx_header_parsed_len_);
+  // Reserve space for body (+ null terminator so protobuf StringRef fields
+  // can be safely null-terminated in-place after decode)
+  if (this->rx_buf_.size() != this->rx_header_parsed_len_ + RX_BUF_NULL_TERMINATOR) {
+    this->rx_buf_.resize(this->rx_header_parsed_len_ + RX_BUF_NULL_TERMINATOR);
   }
 
   if (rx_buf_len_ < rx_header_parsed_len_) {
diff --git a/esphome/components/api/api_pb2.cpp b/esphome/components/api/api_pb2.cpp
index 5c50a8aa5b..9e74d5ddc7 100644
--- a/esphome/components/api/api_pb2.cpp
+++ b/esphome/components/api/api_pb2.cpp
@@ -954,12 +954,66 @@ bool HomeAssistantStateResponse::decode_length(uint32_t field_id, ProtoLengthDel
   return true;
 }
 #endif
+bool DSTRule::decode_varint(uint32_t field_id, ProtoVarInt value) {
+  switch (field_id) {
+    case 1:
+      this->time_seconds = value.as_sint32();
+      break;
+    case 2:
+      this->day = value.as_uint32();
+      break;
+    case 3:
+      this->type = static_cast<enums::DSTRuleType>(value.as_uint32());
+      break;
+    case 4:
+      this->month = value.as_uint32();
+      break;
+    case 5:
+      this->week = value.as_uint32();
+      break;
+    case 6:
+      this->day_of_week = value.as_uint32();
+      break;
+    default:
+      return false;
+  }
+  return true;
+}
+bool ParsedTimezone::decode_varint(uint32_t field_id, ProtoVarInt value) {
+  switch (field_id) {
+    case 1:
+      this->std_offset_seconds = value.as_sint32();
+      break;
+    case 2:
+      this->dst_offset_seconds = value.as_sint32();
+      break;
+    default:
+      return false;
+  }
+  return true;
+}
+bool ParsedTimezone::decode_length(uint32_t field_id, ProtoLengthDelimited value) {
+  switch (field_id) {
+    case 3:
+      value.decode_to_message(this->dst_start);
+      break;
+    case 4:
+      value.decode_to_message(this->dst_end);
+      break;
+    default:
+      return false;
+  }
+  return true;
+}
 bool GetTimeResponse::decode_length(uint32_t field_id, ProtoLengthDelimited value) {
   switch (field_id) {
     case 2: {
       this->timezone = StringRef(reinterpret_cast<const char *>(value.data()), value.size());
       break;
     }
+    case 3:
+      value.decode_to_message(this->parsed_timezone);
+      break;
     default:
       return false;
   }
diff --git a/esphome/components/api/api_pb2.h b/esphome/components/api/api_pb2.h
index 22dc3de995..033b789c18 100644
--- a/esphome/components/api/api_pb2.h
+++ b/esphome/components/api/api_pb2.h
@@ -63,6 +63,12 @@ enum LogLevel : uint32_t {
   LOG_LEVEL_VERBOSE = 6,
   LOG_LEVEL_VERY_VERBOSE = 7,
 };
+enum DSTRuleType : uint32_t {
+  DST_RULE_TYPE_NONE = 0,
+  DST_RULE_TYPE_MONTH_WEEK_DAY = 1,
+  DST_RULE_TYPE_JULIAN_NO_LEAP = 2,
+  DST_RULE_TYPE_DAY_OF_YEAR = 3,
+};
 #ifdef USE_API_USER_DEFINED_ACTIONS
 enum ServiceArgType : uint32_t {
   SERVICE_ARG_TYPE_BOOL = 0,
@@ -1116,15 +1122,45 @@ class GetTimeRequest final : public ProtoMessage {
 
  protected:
 };
+class DSTRule final : public ProtoDecodableMessage {
+ public:
+  int32_t time_seconds{0};
+  uint32_t day{0};
+  enums::DSTRuleType type{};
+  uint32_t month{0};
+  uint32_t week{0};
+  uint32_t day_of_week{0};
+#ifdef HAS_PROTO_MESSAGE_DUMP
+  const char *dump_to(DumpBuffer &out) const override;
+#endif
+
+ protected:
+  bool decode_varint(uint32_t field_id, ProtoVarInt value) override;
+};
+class ParsedTimezone final : public ProtoDecodableMessage {
+ public:
+  int32_t std_offset_seconds{0};
+  int32_t dst_offset_seconds{0};
+  DSTRule dst_start{};
+  DSTRule dst_end{};
+#ifdef HAS_PROTO_MESSAGE_DUMP
+  const char *dump_to(DumpBuffer &out) const override;
+#endif
+
+ protected:
+  bool decode_length(uint32_t field_id, ProtoLengthDelimited value) override;
+  bool decode_varint(uint32_t field_id, ProtoVarInt value) override;
+};
 class GetTimeResponse final : public ProtoDecodableMessage {
  public:
   static constexpr uint8_t MESSAGE_TYPE = 37;
-  static constexpr uint8_t ESTIMATED_SIZE = 14;
+  static constexpr uint8_t ESTIMATED_SIZE = 31;
 #ifdef HAS_PROTO_MESSAGE_DUMP
   const char *message_name() const override { return "get_time_response"; }
 #endif
   uint32_t epoch_seconds{0};
   StringRef timezone{};
+  ParsedTimezone parsed_timezone{};
 #ifdef HAS_PROTO_MESSAGE_DUMP
   const char *dump_to(DumpBuffer &out) const override;
 #endif
diff --git a/esphome/components/api/api_pb2_dump.cpp b/esphome/components/api/api_pb2_dump.cpp
index 52d2486410..4eec42e936 100644
--- a/esphome/components/api/api_pb2_dump.cpp
+++ b/esphome/components/api/api_pb2_dump.cpp
@@ -208,6 +208,20 @@ template<> const char *proto_enum_to_string<enums::LogLevel>(enums::LogLevel val
       return "UNKNOWN";
   }
 }
+template<> const char *proto_enum_to_string<enums::DSTRuleType>(enums::DSTRuleType value) {
+  switch (value) {
+    case enums::DST_RULE_TYPE_NONE:
+      return "DST_RULE_TYPE_NONE";
+    case enums::DST_RULE_TYPE_MONTH_WEEK_DAY:
+      return "DST_RULE_TYPE_MONTH_WEEK_DAY";
+    case enums::DST_RULE_TYPE_JULIAN_NO_LEAP:
+      return "DST_RULE_TYPE_JULIAN_NO_LEAP";
+    case enums::DST_RULE_TYPE_DAY_OF_YEAR:
+      return "DST_RULE_TYPE_DAY_OF_YEAR";
+    default:
+      return "UNKNOWN";
+  }
+}
 #ifdef USE_API_USER_DEFINED_ACTIONS
 template<> const char *proto_enum_to_string<enums::ServiceArgType>(enums::ServiceArgType value) {
   switch (value) {
@@ -1254,10 +1268,35 @@ const char *GetTimeRequest::dump_to(DumpBuffer &out) const {
   out.append("GetTimeRequest {}");
   return out.c_str();
 }
+const char *DSTRule::dump_to(DumpBuffer &out) const {
+  MessageDumpHelper helper(out, "DSTRule");
+  dump_field(out, "time_seconds", this->time_seconds);
+  dump_field(out, "day", this->day);
+  dump_field(out, "type", static_cast<enums::DSTRuleType>(this->type));
+  dump_field(out, "month", this->month);
+  dump_field(out, "week", this->week);
+  dump_field(out, "day_of_week", this->day_of_week);
+  return out.c_str();
+}
+const char *ParsedTimezone::dump_to(DumpBuffer &out) const {
+  MessageDumpHelper helper(out, "ParsedTimezone");
+  dump_field(out, "std_offset_seconds", this->std_offset_seconds);
+  dump_field(out, "dst_offset_seconds", this->dst_offset_seconds);
+  out.append("  dst_start: ");
+  this->dst_start.dump_to(out);
+  out.append("\n");
+  out.append("  dst_end: ");
+  this->dst_end.dump_to(out);
+  out.append("\n");
+  return out.c_str();
+}
 const char *GetTimeResponse::dump_to(DumpBuffer &out) const {
   MessageDumpHelper helper(out, "GetTimeResponse");
   dump_field(out, "epoch_seconds", this->epoch_seconds);
   dump_field(out, "timezone", this->timezone);
+  out.append("  parsed_timezone: ");
+  this->parsed_timezone.dump_to(out);
+  out.append("\n");
   return out.c_str();
 }
 #ifdef USE_API_USER_DEFINED_ACTIONS
diff --git a/esphome/components/api/user_services.cpp b/esphome/components/api/user_services.cpp
index 9c2b4aa79a..28a43c656c 100644
--- a/esphome/components/api/user_services.cpp
+++ b/esphome/components/api/user_services.cpp
@@ -1,5 +1,6 @@
 #include "user_services.h"
 #include "esphome/core/log.h"
+#include "esphome/core/string_ref.h"
 
 namespace esphome::api {
 
@@ -11,6 +12,8 @@ template<> int32_t get_execute_arg_value<int32_t>(const ExecuteServiceArgument &
 }
 template<> float get_execute_arg_value<float>(const ExecuteServiceArgument &arg) { return arg.float_; }
 template<> std::string get_execute_arg_value<std::string>(const ExecuteServiceArgument &arg) { return arg.string_; }
+// Zero-copy StringRef version for YAML-generated services (string_ is null-terminated after decode)
+template<> StringRef get_execute_arg_value<StringRef>(const ExecuteServiceArgument &arg) { return arg.string_; }
 
 // Legacy std::vector versions for external components using custom_api_device.h - optimized with reserve
 template<> std::vector<bool> get_execute_arg_value<std::vector<bool>>(const ExecuteServiceArgument &arg) {
@@ -61,6 +64,8 @@ template<> enums::ServiceArgType to_service_arg_type<bool>() { return enums::SER
 template<> enums::ServiceArgType to_service_arg_type<int32_t>() { return enums::SERVICE_ARG_TYPE_INT; }
 template<> enums::ServiceArgType to_service_arg_type<float>() { return enums::SERVICE_ARG_TYPE_FLOAT; }
 template<> enums::ServiceArgType to_service_arg_type<std::string>() { return enums::SERVICE_ARG_TYPE_STRING; }
+// Zero-copy StringRef version for YAML-generated services
+template<> enums::ServiceArgType to_service_arg_type<StringRef>() { return enums::SERVICE_ARG_TYPE_STRING; }
 
 // Legacy std::vector versions for external components using custom_api_device.h
 template<> enums::ServiceArgType to_service_arg_type<std::vector<bool>>() { return enums::SERVICE_ARG_TYPE_BOOL_ARRAY; }
diff --git a/esphome/components/binary_sensor/__init__.py b/esphome/components/binary_sensor/__init__.py
index 4500168cb1..036d78da73 100644
--- a/esphome/components/binary_sensor/__init__.py
+++ b/esphome/components/binary_sensor/__init__.py
@@ -550,22 +550,8 @@ def binary_sensor_schema(
     return _BINARY_SENSOR_SCHEMA.extend(schema)
 
 
-async def setup_binary_sensor_core_(var, config):
-    await setup_entity(var, config, "binary_sensor")
-
-    if (device_class := config.get(CONF_DEVICE_CLASS)) is not None:
-        cg.add(var.set_device_class(device_class))
-    trigger = config.get(CONF_TRIGGER_ON_INITIAL_STATE, False) or config.get(
-        CONF_PUBLISH_INITIAL_STATE, False
-    )
-    cg.add(var.set_trigger_on_initial_state(trigger))
-    if inverted := config.get(CONF_INVERTED):
-        cg.add(var.set_inverted(inverted))
-    if filters_config := config.get(CONF_FILTERS):
-        cg.add_define("USE_BINARY_SENSOR_FILTER")
-        filters = await cg.build_registry_list(FILTER_REGISTRY, filters_config)
-        cg.add(var.add_filters(filters))
-
+@coroutine_with_priority(CoroPriority.AUTOMATION)
+async def _build_binary_sensor_automations(var, config):
     for conf in config.get(CONF_ON_PRESS, []):
         trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
         await automation.build_automation(trigger, [], conf)
@@ -617,6 +603,25 @@ async def setup_binary_sensor_core_(var, config):
             conf,
         )
 
+
+async def setup_binary_sensor_core_(var, config):
+    await setup_entity(var, config, "binary_sensor")
+
+    if (device_class := config.get(CONF_DEVICE_CLASS)) is not None:
+        cg.add(var.set_device_class(device_class))
+    trigger = config.get(CONF_TRIGGER_ON_INITIAL_STATE, False) or config.get(
+        CONF_PUBLISH_INITIAL_STATE, False
+    )
+    cg.add(var.set_trigger_on_initial_state(trigger))
+    if inverted := config.get(CONF_INVERTED):
+        cg.add(var.set_inverted(inverted))
+    if filters_config := config.get(CONF_FILTERS):
+        cg.add_define("USE_BINARY_SENSOR_FILTER")
+        filters = await cg.build_registry_list(FILTER_REGISTRY, filters_config)
+        cg.add(var.add_filters(filters))
+
+    CORE.add_job(_build_binary_sensor_automations, var, config)
+
     if mqtt_id := config.get(CONF_MQTT_ID):
         mqtt_ = cg.new_Pvariable(mqtt_id, var)
         await mqtt.register_mqtt_component(mqtt_, config)
diff --git a/esphome/components/button/__init__.py b/esphome/components/button/__init__.py
index d2f143b97e..94816a0974 100644
--- a/esphome/components/button/__init__.py
+++ b/esphome/components/button/__init__.py
@@ -123,7 +123,9 @@ BUTTON_PRESS_SCHEMA = maybe_simple_id(
 )
 
 
-@automation.register_action("button.press", PressAction, BUTTON_PRESS_SCHEMA)
+@automation.register_action(
+    "button.press", PressAction, BUTTON_PRESS_SCHEMA, synchronous=True
+)
 async def button_press_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
     return cg.new_Pvariable(action_id, template_arg, paren)
diff --git a/esphome/components/cover/__init__.py b/esphome/components/cover/__init__.py
index 648fe7decf..17095f41f6 100644
--- a/esphome/components/cover/__init__.py
+++ b/esphome/components/cover/__init__.py
@@ -248,25 +248,33 @@ COVER_ACTION_SCHEMA = maybe_simple_id(
 )
 
 
-@automation.register_action("cover.open", OpenAction, COVER_ACTION_SCHEMA)
+@automation.register_action(
+    "cover.open", OpenAction, COVER_ACTION_SCHEMA, synchronous=True
+)
 async def cover_open_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
     return cg.new_Pvariable(action_id, template_arg, paren)
 
 
-@automation.register_action("cover.close", CloseAction, COVER_ACTION_SCHEMA)
+@automation.register_action(
+    "cover.close", CloseAction, COVER_ACTION_SCHEMA, synchronous=True
+)
 async def cover_close_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
     return cg.new_Pvariable(action_id, template_arg, paren)
 
 
-@automation.register_action("cover.stop", StopAction, COVER_ACTION_SCHEMA)
+@automation.register_action(
+    "cover.stop", StopAction, COVER_ACTION_SCHEMA, synchronous=True
+)
 async def cover_stop_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
     return cg.new_Pvariable(action_id, template_arg, paren)
 
 
-@automation.register_action("cover.toggle", ToggleAction, COVER_ACTION_SCHEMA)
+@automation.register_action(
+    "cover.toggle", ToggleAction, COVER_ACTION_SCHEMA, synchronous=True
+)
 async def cover_toggle_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
     return cg.new_Pvariable(action_id, template_arg, paren)
@@ -283,7 +291,9 @@ COVER_CONTROL_ACTION_SCHEMA = cv.Schema(
 )
 
 
-@automation.register_action("cover.control", ControlAction, COVER_CONTROL_ACTION_SCHEMA)
+@automation.register_action(
+    "cover.control", ControlAction, COVER_CONTROL_ACTION_SCHEMA, synchronous=True
+)
 async def cover_control_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
     var = cg.new_Pvariable(action_id, template_arg, paren)
diff --git a/esphome/components/esp32/__init__.py b/esphome/components/esp32/__init__.py
index 998913ecec..dd9e394fd2 100644
--- a/esphome/components/esp32/__init__.py
+++ b/esphome/components/esp32/__init__.py
@@ -952,6 +952,7 @@ CONF_HEAP_IN_IRAM = "heap_in_iram"
 CONF_LOOP_TASK_STACK_SIZE = "loop_task_stack_size"
 CONF_USE_FULL_CERTIFICATE_BUNDLE = "use_full_certificate_bundle"
 CONF_DISABLE_DEBUG_STUBS = "disable_debug_stubs"
+CONF_ENABLE_FULL_PRINTF = "enable_full_printf"
 CONF_DISABLE_OCD_AWARE = "disable_ocd_aware"
 CONF_DISABLE_USB_SERIAL_JTAG_SECONDARY = "disable_usb_serial_jtag_secondary"
 CONF_DISABLE_DEV_NULL_VFS = "disable_dev_null_vfs"
@@ -1126,6 +1127,7 @@ FRAMEWORK_SCHEMA = cv.Schema(
                 cv.Optional(
                     CONF_INCLUDE_BUILTIN_IDF_COMPONENTS, default=[]
                 ): cv.ensure_list(cv.string_strict),
+                cv.Optional(CONF_ENABLE_FULL_PRINTF, default=False): cv.boolean,
                 cv.Optional(CONF_DISABLE_DEBUG_STUBS, default=True): cv.boolean,
                 cv.Optional(CONF_DISABLE_OCD_AWARE, default=True): cv.boolean,
                 cv.Optional(
@@ -1469,6 +1471,14 @@ async def to_code(config):
             "_ZSt25__throw_bad_function_callv",
         ]:
             cg.add_build_flag(f"-Wl,--wrap={mangled}")
+
+        # Wrap FILE*-based printf functions to eliminate newlib's _vfprintf_r
+        # (~11 KB). See printf_stubs.cpp for implementation.
+        if conf[CONF_ADVANCED][CONF_ENABLE_FULL_PRINTF]:
+            cg.add_define("USE_FULL_PRINTF")
+        else:
+            for symbol in ("vprintf", "printf", "fprintf"):
+                cg.add_build_flag(f"-Wl,--wrap={symbol}")
     else:
         cg.add_build_flag("-DUSE_ARDUINO")
         cg.add_build_flag("-DUSE_ESP32_FRAMEWORK_ARDUINO")
diff --git a/esphome/components/esp32/preferences.cpp b/esphome/components/esp32/preferences.cpp
index 8d6fdc86f6..a3ef10b21f 100644
--- a/esphome/components/esp32/preferences.cpp
+++ b/esphome/components/esp32/preferences.cpp
@@ -19,16 +19,7 @@ static constexpr size_t KEY_BUFFER_SIZE = 12;
 
 struct NVSData {
   uint32_t key;
-  std::unique_ptr<uint8_t[]> data;
-  size_t len;
-
-  void set_data(const uint8_t *src, size_t size) {
-    if (!this->data || this->len != size) {
-      this->data = std::make_unique<uint8_t[]>(size);
-      this->len = size;
-    }
-    memcpy(this->data.get(), src, size);
-  }
+  SmallInlineBuffer<8> data;  // Most prefs fit in 8 bytes (covers fan, cover, select, etc.)
 };
 
 static std::vector<NVSData> s_pending_save;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
@@ -41,14 +32,14 @@ class ESP32PreferenceBackend : public ESPPreferenceBackend {
     // try find in pending saves and update that
     for (auto &obj : s_pending_save) {
       if (obj.key == this->key) {
-        obj.set_data(data, len);
+        obj.data.set(data, len);
         return true;
       }
     }
     NVSData save{};
     save.key = this->key;
-    save.set_data(data, len);
-    s_pending_save.emplace_back(std::move(save));
+    save.data.set(data, len);
+    s_pending_save.push_back(std::move(save));
     ESP_LOGVV(TAG, "s_pending_save: key: %" PRIu32 ", len: %zu", this->key, len);
     return true;
   }
@@ -56,11 +47,11 @@ class ESP32PreferenceBackend : public ESPPreferenceBackend {
     // try find in pending saves and load from that
     for (auto &obj : s_pending_save) {
       if (obj.key == this->key) {
-        if (obj.len != len) {
+        if (obj.data.size() != len) {
           // size mismatch
           return false;
         }
-        memcpy(data, obj.data.get(), len);
+        memcpy(data, obj.data.data(), len);
         return true;
       }
     }
@@ -133,10 +124,10 @@ class ESP32Preferences : public ESPPreferences {
       snprintf(key_str, sizeof(key_str), "%" PRIu32, save.key);
       ESP_LOGVV(TAG, "Checking if NVS data %s has changed", key_str);
       if (this->is_changed_(this->nvs_handle, save, key_str)) {
-        esp_err_t err = nvs_set_blob(this->nvs_handle, key_str, save.data.get(), save.len);
-        ESP_LOGV(TAG, "sync: key: %s, len: %zu", key_str, save.len);
+        esp_err_t err = nvs_set_blob(this->nvs_handle, key_str, save.data.data(), save.data.size());
+        ESP_LOGV(TAG, "sync: key: %s, len: %zu", key_str, save.data.size());
         if (err != 0) {
-          ESP_LOGV(TAG, "nvs_set_blob('%s', len=%zu) failed: %s", key_str, save.len, esp_err_to_name(err));
+          ESP_LOGV(TAG, "nvs_set_blob('%s', len=%zu) failed: %s", key_str, save.data.size(), esp_err_to_name(err));
           failed++;
           last_err = err;
           last_key = save.key;
@@ -144,7 +135,7 @@ class ESP32Preferences : public ESPPreferences {
         }
         written++;
       } else {
-        ESP_LOGV(TAG, "NVS data not changed skipping %" PRIu32 "  len=%zu", save.key, save.len);
+        ESP_LOGV(TAG, "NVS data not changed skipping %" PRIu32 "  len=%zu", save.key, save.data.size());
         cached++;
       }
     }
@@ -176,7 +167,7 @@ class ESP32Preferences : public ESPPreferences {
       return true;
     }
     // Check size first before allocating memory
-    if (actual_len != to_save.len) {
+    if (actual_len != to_save.data.size()) {
       return true;
     }
     // Most preferences are small, use stack buffer with heap fallback for large ones
@@ -186,7 +177,7 @@ class ESP32Preferences : public ESPPreferences {
       ESP_LOGV(TAG, "nvs_get_blob('%s') failed: %s", key_str, esp_err_to_name(err));
       return true;
     }
-    return memcmp(to_save.data.get(), stored_data.get(), to_save.len) != 0;
+    return memcmp(to_save.data.data(), stored_data.get(), to_save.data.size()) != 0;
   }
 
   bool reset() override {
diff --git a/esphome/components/esp32/printf_stubs.cpp b/esphome/components/esp32/printf_stubs.cpp
new file mode 100644
index 0000000000..c6f03bc363
--- /dev/null
+++ b/esphome/components/esp32/printf_stubs.cpp
@@ -0,0 +1,85 @@
+/*
+ * Linker wrap stubs for FILE*-based printf functions.
+ *
+ * ESP-IDF SDK components (gpio driver, ringbuf, log_write) reference
+ * fprintf(), printf(), and vprintf() which pull in newlib's _vfprintf_r
+ * (~11 KB). This is a separate implementation from _svfprintf_r (used by
+ * snprintf/vsnprintf) that handles FILE* stream I/O with buffering and
+ * locking.
+ *
+ * ESPHome replaces the ESP-IDF log handler via esp_log_set_vprintf_(),
+ * so the SDK's vprintf() path is dead code at runtime. The fprintf()
+ * and printf() calls in SDK components are only in debug/assert paths
+ * (gpio_dump_io_configuration, ringbuf diagnostics) that are either
+ * GC'd or never called. Crash backtraces and panic output are
+ * unaffected — they use esp_rom_printf() which is a ROM function
+ * and does not go through libc.
+ *
+ * These stubs redirect through vsnprintf() (which uses _svfprintf_r
+ * already in the binary) and fwrite(), allowing the linker to
+ * dead-code eliminate _vfprintf_r.
+ *
+ * Saves ~11 KB of flash.
+ *
+ * To disable these wraps, set enable_full_printf: true in the esp32
+ * advanced config section.
+ */
+
+#if defined(USE_ESP_IDF) && !defined(USE_FULL_PRINTF)
+#include <cstdarg>
+#include <cstdio>
+
+#include "esp_system.h"
+
+namespace esphome::esp32 {}
+
+static constexpr size_t PRINTF_BUFFER_SIZE = 512;
+
+// These stubs are essentially dead code at runtime — ESPHome replaces the
+// ESP-IDF log handler, and the SDK's printf/fprintf calls only exist in
+// debug/assert paths that are never reached in normal operation.
+// The buffer overflow check is purely defensive and should never trigger.
+static int write_printf_buffer(FILE *stream, char *buf, int len) {
+  if (len < 0) {
+    return len;
+  }
+  size_t write_len = len;
+  if (write_len >= PRINTF_BUFFER_SIZE) {
+    fwrite(buf, 1, PRINTF_BUFFER_SIZE - 1, stream);
+    esp_system_abort("printf buffer overflow; set enable_full_printf: true in esp32 framework advanced config");
+  }
+  if (fwrite(buf, 1, write_len, stream) < write_len || ferror(stream)) {
+    return -1;
+  }
+  return len;
+}
+
+// NOLINTBEGIN(bugprone-reserved-identifier,cert-dcl37-c,cert-dcl51-cpp,readability-identifier-naming)
+extern "C" {
+
+int __wrap_vprintf(const char *fmt, va_list ap) {
+  char buf[PRINTF_BUFFER_SIZE];
+  return write_printf_buffer(stdout, buf, vsnprintf(buf, sizeof(buf), fmt, ap));
+}
+
+int __wrap_printf(const char *fmt, ...) {
+  va_list ap;
+  va_start(ap, fmt);
+  int len = __wrap_vprintf(fmt, ap);
+  va_end(ap);
+  return len;
+}
+
+int __wrap_fprintf(FILE *stream, const char *fmt, ...) {
+  va_list ap;
+  va_start(ap, fmt);
+  char buf[PRINTF_BUFFER_SIZE];
+  int len = write_printf_buffer(stream, buf, vsnprintf(buf, sizeof(buf), fmt, ap));
+  va_end(ap);
+  return len;
+}
+
+}  // extern "C"
+// NOLINTEND(bugprone-reserved-identifier,cert-dcl37-c,cert-dcl51-cpp,readability-identifier-naming)
+
+#endif  // USE_ESP_IDF && !USE_FULL_PRINTF
diff --git a/esphome/components/fan/__init__.py b/esphome/components/fan/__init__.py
index 6010aa8ed4..e839df6aee 100644
--- a/esphome/components/fan/__init__.py
+++ b/esphome/components/fan/__init__.py
@@ -311,13 +311,17 @@ FAN_ACTION_SCHEMA = maybe_simple_id(
 )
 
 
-@automation.register_action("fan.toggle", ToggleAction, FAN_ACTION_SCHEMA)
+@automation.register_action(
+    "fan.toggle", ToggleAction, FAN_ACTION_SCHEMA, synchronous=True
+)
 async def fan_toggle_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
     return cg.new_Pvariable(action_id, template_arg, paren)
 
 
-@automation.register_action("fan.turn_off", TurnOffAction, FAN_ACTION_SCHEMA)
+@automation.register_action(
+    "fan.turn_off", TurnOffAction, FAN_ACTION_SCHEMA, synchronous=True
+)
 async def fan_turn_off_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
     return cg.new_Pvariable(action_id, template_arg, paren)
@@ -336,6 +340,7 @@ async def fan_turn_off_to_code(config, action_id, template_arg, args):
             ),
         }
     ),
+    synchronous=True,
 )
 async def fan_turn_on_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
diff --git a/esphome/components/globals/__init__.py b/esphome/components/globals/__init__.py
index fc400c5dd1..fe11a93a4b 100644
--- a/esphome/components/globals/__init__.py
+++ b/esphome/components/globals/__init__.py
@@ -102,6 +102,7 @@ async def to_code(config):
             cv.Required(CONF_VALUE): cv.templatable(cv.string_strict),
         }
     ),
+    synchronous=True,
 )
 async def globals_set_to_code(config, action_id, template_arg, args):
     full_id, paren = await cg.get_variable_with_full_id(config[CONF_ID])
diff --git a/esphome/components/gt911/touchscreen/__init__.py b/esphome/components/gt911/touchscreen/__init__.py
index 6c80ff280f..b850eeea8b 100644
--- a/esphome/components/gt911/touchscreen/__init__.py
+++ b/esphome/components/gt911/touchscreen/__init__.py
@@ -16,7 +16,7 @@ GT911Touchscreen = gt911_ns.class_(
 CONFIG_SCHEMA = touchscreen.TOUCHSCREEN_SCHEMA.extend(
     {
         cv.GenerateID(): cv.declare_id(GT911Touchscreen),
-        cv.Optional(CONF_INTERRUPT_PIN): pins.internal_gpio_input_pin_schema,
+        cv.Optional(CONF_INTERRUPT_PIN): pins.gpio_output_pin_schema,
         cv.Optional(CONF_RESET_PIN): pins.gpio_output_pin_schema,
     }
 ).extend(i2c.i2c_device_schema(0x5D))
diff --git a/esphome/components/gt911/touchscreen/gt911_touchscreen.cpp b/esphome/components/gt911/touchscreen/gt911_touchscreen.cpp
index b11880a042..17bfa82cb4 100644
--- a/esphome/components/gt911/touchscreen/gt911_touchscreen.cpp
+++ b/esphome/components/gt911/touchscreen/gt911_touchscreen.cpp
@@ -2,6 +2,7 @@
 
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
+#include "esphome/core/gpio.h"
 
 namespace esphome {
 namespace gt911 {
@@ -26,15 +27,17 @@ static const size_t MAX_BUTTONS = 4;  // max number of buttons scanned
 
 void GT911Touchscreen::setup() {
   if (this->reset_pin_ != nullptr) {
+    // temporarily set the interrupt pin to output to control address selection
     this->reset_pin_->setup();
     this->reset_pin_->digital_write(false);
     if (this->interrupt_pin_ != nullptr) {
-      // temporarily set the interrupt pin to output to control address selection
+      this->interrupt_pin_->setup();
       this->interrupt_pin_->pin_mode(gpio::FLAG_OUTPUT);
       this->interrupt_pin_->digital_write(false);
     }
     delay(2);
-    this->reset_pin_->digital_write(true);  // wait at least T3+T4 ms as per the datasheet
+    this->reset_pin_->digital_write(true);
+    // wait at least T3+T4 ms as per the datasheet
     this->set_timeout(5 + 50 + 1, [this] { this->setup_internal_(); });
     return;
   }
@@ -43,11 +46,10 @@ void GT911Touchscreen::setup() {
 
 void GT911Touchscreen::setup_internal_() {
   if (this->interrupt_pin_ != nullptr) {
-    // set pre-configured input mode
-    this->interrupt_pin_->setup();
+    if (this->interrupt_pin_->is_internal())
+      this->interrupt_pin_->pin_mode(gpio::FLAG_INPUT);
   }
 
-  // check the configuration of the int line.
   uint8_t data[4];
   i2c::ErrorCode err = this->write(GET_SWITCHES, sizeof(GET_SWITCHES));
   if (err != i2c::ERROR_OK && this->address_ == PRIMARY_ADDRESS) {
@@ -58,12 +60,25 @@ void GT911Touchscreen::setup_internal_() {
     err = this->read(data, 1);
     if (err == i2c::ERROR_OK) {
       ESP_LOGD(TAG, "Switches ADDR: 0x%02X DATA: 0x%02X", this->address_, data[0]);
+
+      // data[0] & 1 == 1  =>  controller uses falling edge  =>  active-low
+      // data[0] & 1 == 0  =>  controller uses rising  edge  =>  active-high
+      bool active_high = !(data[0] & 1);
+
       if (this->interrupt_pin_ != nullptr) {
-        this->attach_interrupt_(this->interrupt_pin_,
-                                (data[0] & 1) ? gpio::INTERRUPT_FALLING_EDGE : gpio::INTERRUPT_RISING_EDGE);
+        if (this->interrupt_pin_->is_internal()) {
+          // Direct MCU pin: attach a hardware interrupt, no polling needed.
+          this->attach_interrupt_(static_cast<InternalGPIOPin *>(this->interrupt_pin_),
+                                  active_high ? gpio::INTERRUPT_RISING_EDGE : gpio::INTERRUPT_FALLING_EDGE);
+          ESP_LOGD(TAG, "Interrupt pin: hardware interrupt, active %s", active_high ? "HIGH" : "LOW");
+        } else {
+          // IO expander pin: leave as output for configuration only.
+          ESP_LOGD(TAG, "Interrupt pin: IO expander polling mode, active %s", active_high ? "HIGH" : "LOW");
+        }
       }
     }
   }
+
   if (this->x_raw_max_ == 0 || this->y_raw_max_ == 0) {
     // no calibration? Attempt to read the max values from the touchscreen.
     if (err == i2c::ERROR_OK) {
diff --git a/esphome/components/gt911/touchscreen/gt911_touchscreen.h b/esphome/components/gt911/touchscreen/gt911_touchscreen.h
index 85025b5522..a6577b5879 100644
--- a/esphome/components/gt911/touchscreen/gt911_touchscreen.h
+++ b/esphome/components/gt911/touchscreen/gt911_touchscreen.h
@@ -30,7 +30,9 @@ class GT911Touchscreen : public touchscreen::Touchscreen, public i2c::I2CDevice
   void dump_config() override;
   bool can_proceed() override { return this->setup_done_; }
 
-  void set_interrupt_pin(InternalGPIOPin *pin) { this->interrupt_pin_ = pin; }
+  /// Set a interrupt pin (supports hardware interrupts or expander connected).
+  void set_interrupt_pin(GPIOPin *pin) { this->interrupt_pin_ = pin; }
+
   void set_reset_pin(GPIOPin *pin) { this->reset_pin_ = pin; }
   void register_button_listener(GT911ButtonListener *listener) { this->button_listeners_.push_back(listener); }
 
@@ -49,7 +51,7 @@ class GT911Touchscreen : public touchscreen::Touchscreen, public i2c::I2CDevice
   /// @brief True if the touchscreen setup has completed successfully.
   bool setup_done_{false};
 
-  InternalGPIOPin *interrupt_pin_{nullptr};
+  GPIOPin *interrupt_pin_{nullptr};
   GPIOPin *reset_pin_{nullptr};
   std::vector<GT911ButtonListener *> button_listeners_;
   uint8_t button_state_{0xFF};  // last button state. Initial FF guarantees first update.
diff --git a/esphome/components/improv_serial/__init__.py b/esphome/components/improv_serial/__init__.py
index 9a2ac2f40f..4266f5b78b 100644
--- a/esphome/components/improv_serial/__init__.py
+++ b/esphome/components/improv_serial/__init__.py
@@ -43,3 +43,4 @@ async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await cg.register_component(var, config)
     await improv_base.setup_improv_core(var, config, "improv_serial")
+    cg.add_define("USE_IMPROV_SERIAL")
diff --git a/esphome/components/ld2410/ld2410.cpp b/esphome/components/ld2410/ld2410.cpp
index dd1d53857d..f10e7ec0aa 100644
--- a/esphome/components/ld2410/ld2410.cpp
+++ b/esphome/components/ld2410/ld2410.cpp
@@ -173,8 +173,6 @@ static constexpr uint8_t DATA_FRAME_FOOTER[HEADER_FOOTER_SIZE] = {0xF8, 0xF7, 0x
 // MAC address the module uses when Bluetooth is disabled
 static constexpr uint8_t NO_MAC[] = {0x08, 0x05, 0x04, 0x03, 0x02, 0x01};
 
-static inline int two_byte_to_int(char firstbyte, char secondbyte) { return (int16_t) (secondbyte << 8) + firstbyte; }
-
 static inline bool validate_header_footer(const uint8_t *header_footer, const uint8_t *buffer) {
   return std::memcmp(header_footer, buffer, HEADER_FOOTER_SIZE) == 0;
 }
@@ -361,17 +359,14 @@ void LD2410Component::handle_periodic_data_() {
     Detect distance: 16~17th bytes
   */
 #ifdef USE_SENSOR
-  SAFE_PUBLISH_SENSOR(
-      this->moving_target_distance_sensor_,
-      ld2410::two_byte_to_int(this->buffer_data_[MOVING_TARGET_LOW], this->buffer_data_[MOVING_TARGET_HIGH]))
+  SAFE_PUBLISH_SENSOR(this->moving_target_distance_sensor_,
+                      encode_uint16(this->buffer_data_[MOVING_TARGET_HIGH], this->buffer_data_[MOVING_TARGET_LOW]))
   SAFE_PUBLISH_SENSOR(this->moving_target_energy_sensor_, this->buffer_data_[MOVING_ENERGY])
-  SAFE_PUBLISH_SENSOR(
-      this->still_target_distance_sensor_,
-      ld2410::two_byte_to_int(this->buffer_data_[STILL_TARGET_LOW], this->buffer_data_[STILL_TARGET_HIGH]));
+  SAFE_PUBLISH_SENSOR(this->still_target_distance_sensor_,
+                      encode_uint16(this->buffer_data_[STILL_TARGET_HIGH], this->buffer_data_[STILL_TARGET_LOW]));
   SAFE_PUBLISH_SENSOR(this->still_target_energy_sensor_, this->buffer_data_[STILL_ENERGY]);
-  SAFE_PUBLISH_SENSOR(
-      this->detection_distance_sensor_,
-      ld2410::two_byte_to_int(this->buffer_data_[DETECT_DISTANCE_LOW], this->buffer_data_[DETECT_DISTANCE_HIGH]));
+  SAFE_PUBLISH_SENSOR(this->detection_distance_sensor_,
+                      encode_uint16(this->buffer_data_[DETECT_DISTANCE_HIGH], this->buffer_data_[DETECT_DISTANCE_LOW]));
 
   if (engineering_mode) {
     /*
@@ -578,8 +573,8 @@ bool LD2410Component::handle_ack_data_() {
       /*
         None Duration: 33~34th bytes
       */
-      updates.push_back(set_number_value(this->timeout_number_,
-                                         ld2410::two_byte_to_int(this->buffer_data_[32], this->buffer_data_[33])));
+      updates.push_back(
+          set_number_value(this->timeout_number_, encode_uint16(this->buffer_data_[33], this->buffer_data_[32])));
       for (auto &update : updates) {
         update();
       }
diff --git a/esphome/components/ld2412/ld2412.cpp b/esphome/components/ld2412/ld2412.cpp
index 484d5bd281..ef0915d0bc 100644
--- a/esphome/components/ld2412/ld2412.cpp
+++ b/esphome/components/ld2412/ld2412.cpp
@@ -192,8 +192,6 @@ static constexpr uint8_t DATA_FRAME_FOOTER[HEADER_FOOTER_SIZE] = {0xF8, 0xF7, 0x
 // MAC address the module uses when Bluetooth is disabled
 static constexpr uint8_t NO_MAC[] = {0x08, 0x05, 0x04, 0x03, 0x02, 0x01};
 
-static inline int two_byte_to_int(char firstbyte, char secondbyte) { return (int16_t) (secondbyte << 8) + firstbyte; }
-
 static inline bool validate_header_footer(const uint8_t *header_footer, const uint8_t *buffer) {
   return std::memcmp(header_footer, buffer, HEADER_FOOTER_SIZE) == 0;
 }
@@ -398,22 +396,19 @@ void LD2412Component::handle_periodic_data_() {
     Detect distance: 16~17th bytes
   */
 #ifdef USE_SENSOR
-  SAFE_PUBLISH_SENSOR(
-      this->moving_target_distance_sensor_,
-      ld2412::two_byte_to_int(this->buffer_data_[MOVING_TARGET_LOW], this->buffer_data_[MOVING_TARGET_HIGH]))
+  SAFE_PUBLISH_SENSOR(this->moving_target_distance_sensor_,
+                      encode_uint16(this->buffer_data_[MOVING_TARGET_HIGH], this->buffer_data_[MOVING_TARGET_LOW]))
   SAFE_PUBLISH_SENSOR(this->moving_target_energy_sensor_, this->buffer_data_[MOVING_ENERGY])
-  SAFE_PUBLISH_SENSOR(
-      this->still_target_distance_sensor_,
-      ld2412::two_byte_to_int(this->buffer_data_[STILL_TARGET_LOW], this->buffer_data_[STILL_TARGET_HIGH]))
+  SAFE_PUBLISH_SENSOR(this->still_target_distance_sensor_,
+                      encode_uint16(this->buffer_data_[STILL_TARGET_HIGH], this->buffer_data_[STILL_TARGET_LOW]))
   SAFE_PUBLISH_SENSOR(this->still_target_energy_sensor_, this->buffer_data_[STILL_ENERGY])
   if (this->detection_distance_sensor_ != nullptr) {
     int new_detect_distance = 0;
     if (target_state != 0x00 && (target_state & MOVE_BITMASK)) {
       new_detect_distance =
-          ld2412::two_byte_to_int(this->buffer_data_[MOVING_TARGET_LOW], this->buffer_data_[MOVING_TARGET_HIGH]);
+          encode_uint16(this->buffer_data_[MOVING_TARGET_HIGH], this->buffer_data_[MOVING_TARGET_LOW]);
     } else if (target_state != 0x00) {
-      new_detect_distance =
-          ld2412::two_byte_to_int(this->buffer_data_[STILL_TARGET_LOW], this->buffer_data_[STILL_TARGET_HIGH]);
+      new_detect_distance = encode_uint16(this->buffer_data_[STILL_TARGET_HIGH], this->buffer_data_[STILL_TARGET_LOW]);
     }
     this->detection_distance_sensor_->publish_state_if_not_dup(new_detect_distance);
   }
@@ -637,9 +632,9 @@ bool LD2412Component::handle_ack_data_() {
       /*
         None Duration: 11~12th bytes
       */
-      updates.push_back(set_number_value(this->timeout_number_,
-                                         ld2412::two_byte_to_int(this->buffer_data_[12], this->buffer_data_[13])));
-      ESP_LOGV(TAG, "timeout_number_: %u", ld2412::two_byte_to_int(this->buffer_data_[12], this->buffer_data_[13]));
+      updates.push_back(
+          set_number_value(this->timeout_number_, encode_uint16(this->buffer_data_[13], this->buffer_data_[12])));
+      ESP_LOGV(TAG, "timeout_number_: %u", encode_uint16(this->buffer_data_[13], this->buffer_data_[12]));
       /*
         Output pin configuration: 13th bytes
       */
diff --git a/esphome/components/ld2450/ld2450.cpp b/esphome/components/ld2450/ld2450.cpp
index d30c164769..583918e5f5 100644
--- a/esphome/components/ld2450/ld2450.cpp
+++ b/esphome/components/ld2450/ld2450.cpp
@@ -168,15 +168,6 @@ static inline int16_t hex_to_signed_int(const uint8_t *buffer, uint8_t offset) {
   return dec_val;
 }
 
-static inline float calculate_angle(float base, float hypotenuse) {
-  if (base < 0.0f || hypotenuse <= 0.0f) {
-    return 0.0f;
-  }
-  float angle_radians = acosf(base / hypotenuse);
-  float angle_degrees = angle_radians * (180.0f / std::numbers::pi_v<float>);
-  return angle_degrees;
-}
-
 static inline bool validate_header_footer(const uint8_t *header_footer, const uint8_t *buffer) {
   return std::memcmp(header_footer, buffer, HEADER_FOOTER_SIZE) == 0;
 }
@@ -292,16 +283,19 @@ void LD2450Component::loop() {
   }
 }
 
-// Count targets in zone
-uint8_t LD2450Component::count_targets_in_zone_(const Zone &zone, bool is_moving) {
-  uint8_t count = 0;
-  for (auto &index : this->target_info_) {
-    if (index.x > zone.x1 && index.x < zone.x2 && index.y > zone.y1 && index.y < zone.y2 &&
-        index.is_moving == is_moving) {
-      count++;
+// Count targets in zone (single pass for both still and moving)
+void LD2450Component::count_targets_in_zone_(const Zone &zone, uint8_t &still, uint8_t &moving) {
+  still = 0;
+  moving = 0;
+  for (auto &target : this->target_info_) {
+    if (target.x > zone.x1 && target.x < zone.x2 && target.y > zone.y1 && target.y < zone.y2) {
+      if (target.is_moving) {
+        moving++;
+      } else {
+        still++;
+      }
     }
   }
-  return count;
 }
 
 // Service reset_radar_zone
@@ -510,11 +504,8 @@ void LD2450Component::handle_periodic_data_() {
     }
 #ifdef USE_SENSOR
     SAFE_PUBLISH_SENSOR(this->move_distance_sensors_[index], td);
-    // ANGLE
-    angle = ld2450::calculate_angle(static_cast<float>(ty), static_cast<float>(td));
-    if (tx > 0) {
-      angle = angle * -1;
-    }
+    // ANGLE - atan2f computes angle from Y axis directly, no sqrt/division needed
+    angle = atan2f(static_cast<float>(-tx), static_cast<float>(ty)) * (180.0f / std::numbers::pi_v<float>);
     SAFE_PUBLISH_SENSOR(this->move_angle_sensors_[index], angle);
 #endif
 #ifdef USE_TEXT_SENSOR
@@ -528,10 +519,11 @@ void LD2450Component::handle_periodic_data_() {
     } else {
       direction = DIRECTION_STATIONARY;
     }
-    text_sensor::TextSensor *tsd = this->direction_text_sensors_[index];
-    const auto *dir_str = find_str(ld2450::DIRECTION_BY_UINT, direction);
-    if (tsd != nullptr && (!tsd->has_state() || tsd->get_state() != dir_str)) {
-      tsd->publish_state(dir_str);
+    if (this->direction_dedup_[index].next(direction)) {
+      text_sensor::TextSensor *tsd = this->direction_text_sensors_[index];
+      if (tsd != nullptr) {
+        tsd->publish_state(find_str(ld2450::DIRECTION_BY_UINT, direction));
+      }
     }
 #endif
 
@@ -551,8 +543,7 @@ void LD2450Component::handle_periodic_data_() {
   uint8_t zone_moving_targets = 0;
   uint8_t zone_all_targets = 0;
   for (index = 0; index < MAX_ZONES; index++) {
-    zone_still_targets = this->count_targets_in_zone_(this->zone_config_[index], false);
-    zone_moving_targets = this->count_targets_in_zone_(this->zone_config_[index], true);
+    this->count_targets_in_zone_(this->zone_config_[index], zone_still_targets, zone_moving_targets);
     zone_all_targets = zone_still_targets + zone_moving_targets;
 
     // Publish Still Target Count in Zones
diff --git a/esphome/components/ld2450/ld2450.h b/esphome/components/ld2450/ld2450.h
index 30f96c0a9c..39b0ebd9da 100644
--- a/esphome/components/ld2450/ld2450.h
+++ b/esphome/components/ld2450/ld2450.h
@@ -163,7 +163,7 @@ class LD2450Component : public Component, public uart::UARTDevice {
   void save_to_flash_(float value);
   float restore_from_flash_();
   bool get_timeout_status_(uint32_t check_millis);
-  uint8_t count_targets_in_zone_(const Zone &zone, bool is_moving);
+  void count_targets_in_zone_(const Zone &zone, uint8_t &still, uint8_t &moving);
 
   uint32_t presence_millis_ = 0;
   uint32_t still_presence_millis_ = 0;
@@ -194,7 +194,8 @@ class LD2450Component : public Component, public uart::UARTDevice {
   std::array<SensorWithDedup<uint8_t> *, MAX_ZONES> zone_moving_target_count_sensors_{};
 #endif
 #ifdef USE_TEXT_SENSOR
-  std::array<text_sensor::TextSensor *, 3> direction_text_sensors_{};
+  std::array<text_sensor::TextSensor *, MAX_TARGETS> direction_text_sensors_{};
+  std::array<Deduplicator<uint8_t>, MAX_TARGETS> direction_dedup_{};
 #endif
 
   LazyCallbackManager<void()> data_callback_;
diff --git a/esphome/components/libretiny/preferences.cpp b/esphome/components/libretiny/preferences.cpp
index 740c1a233a..1c101136e1 100644
--- a/esphome/components/libretiny/preferences.cpp
+++ b/esphome/components/libretiny/preferences.cpp
@@ -17,16 +17,7 @@ static constexpr size_t KEY_BUFFER_SIZE = 12;
 
 struct NVSData {
   uint32_t key;
-  std::unique_ptr<uint8_t[]> data;
-  size_t len;
-
-  void set_data(const uint8_t *src, size_t size) {
-    if (!this->data || this->len != size) {
-      this->data = std::make_unique<uint8_t[]>(size);
-      this->len = size;
-    }
-    memcpy(this->data.get(), src, size);
-  }
+  SmallInlineBuffer<8> data;  // Most prefs fit in 8 bytes (covers fan, cover, select, etc.)
 };
 
 static std::vector<NVSData> s_pending_save;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
@@ -41,14 +32,14 @@ class LibreTinyPreferenceBackend : public ESPPreferenceBackend {
     // try find in pending saves and update that
     for (auto &obj : s_pending_save) {
       if (obj.key == this->key) {
-        obj.set_data(data, len);
+        obj.data.set(data, len);
         return true;
       }
     }
     NVSData save{};
     save.key = this->key;
-    save.set_data(data, len);
-    s_pending_save.emplace_back(std::move(save));
+    save.data.set(data, len);
+    s_pending_save.push_back(std::move(save));
     ESP_LOGVV(TAG, "s_pending_save: key: %" PRIu32 ", len: %zu", this->key, len);
     return true;
   }
@@ -57,11 +48,11 @@ class LibreTinyPreferenceBackend : public ESPPreferenceBackend {
     // try find in pending saves and load from that
     for (auto &obj : s_pending_save) {
       if (obj.key == this->key) {
-        if (obj.len != len) {
+        if (obj.data.size() != len) {
           // size mismatch
           return false;
         }
-        memcpy(data, obj.data.get(), len);
+        memcpy(data, obj.data.data(), len);
         return true;
       }
     }
@@ -122,11 +113,11 @@ class LibreTinyPreferences : public ESPPreferences {
       snprintf(key_str, sizeof(key_str), "%" PRIu32, save.key);
       ESP_LOGVV(TAG, "Checking if FDB data %s has changed", key_str);
       if (this->is_changed_(&this->db, save, key_str)) {
-        ESP_LOGV(TAG, "sync: key: %s, len: %zu", key_str, save.len);
-        fdb_blob_make(&this->blob, save.data.get(), save.len);
+        ESP_LOGV(TAG, "sync: key: %s, len: %zu", key_str, save.data.size());
+        fdb_blob_make(&this->blob, save.data.data(), save.data.size());
         fdb_err_t err = fdb_kv_set_blob(&this->db, key_str, &this->blob);
         if (err != FDB_NO_ERR) {
-          ESP_LOGV(TAG, "fdb_kv_set_blob('%s', len=%zu) failed: %d", key_str, save.len, err);
+          ESP_LOGV(TAG, "fdb_kv_set_blob('%s', len=%zu) failed: %d", key_str, save.data.size(), err);
           failed++;
           last_err = err;
           last_key = save.key;
@@ -134,7 +125,7 @@ class LibreTinyPreferences : public ESPPreferences {
         }
         written++;
       } else {
-        ESP_LOGD(TAG, "FDB data not changed; skipping %" PRIu32 "  len=%zu", save.key, save.len);
+        ESP_LOGD(TAG, "FDB data not changed; skipping %" PRIu32 "  len=%zu", save.key, save.data.size());
         cached++;
       }
     }
@@ -159,7 +150,7 @@ class LibreTinyPreferences : public ESPPreferences {
     }
 
     // Check size first - if different, data has changed
-    if (kv.value_len != to_save.len) {
+    if (kv.value_len != to_save.data.size()) {
       return true;
     }
 
@@ -173,7 +164,7 @@ class LibreTinyPreferences : public ESPPreferences {
     }
 
     // Compare the actual data
-    return memcmp(to_save.data.get(), stored_data.get(), kv.value_len) != 0;
+    return memcmp(to_save.data.data(), stored_data.get(), kv.value_len) != 0;
   }
 
   bool reset() override {
diff --git a/esphome/components/light/automation.py b/esphome/components/light/automation.py
index e5aa8fa0e9..89b2fc0fb2 100644
--- a/esphome/components/light/automation.py
+++ b/esphome/components/light/automation.py
@@ -51,6 +51,7 @@ from .types import (
             ),
         }
     ),
+    synchronous=True,
 )
 async def light_toggle_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
@@ -111,13 +112,13 @@ LIGHT_TURN_ON_ACTION_SCHEMA = automation.maybe_simple_id(
 
 
 @automation.register_action(
-    "light.turn_off", LightControlAction, LIGHT_TURN_OFF_ACTION_SCHEMA
+    "light.turn_off", LightControlAction, LIGHT_TURN_OFF_ACTION_SCHEMA, synchronous=True
 )
 @automation.register_action(
-    "light.turn_on", LightControlAction, LIGHT_TURN_ON_ACTION_SCHEMA
+    "light.turn_on", LightControlAction, LIGHT_TURN_ON_ACTION_SCHEMA, synchronous=True
 )
 @automation.register_action(
-    "light.control", LightControlAction, LIGHT_CONTROL_ACTION_SCHEMA
+    "light.control", LightControlAction, LIGHT_CONTROL_ACTION_SCHEMA, synchronous=True
 )
 async def light_control_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
@@ -193,7 +194,10 @@ LIGHT_DIM_RELATIVE_ACTION_SCHEMA = cv.Schema(
 
 
 @automation.register_action(
-    "light.dim_relative", DimRelativeAction, LIGHT_DIM_RELATIVE_ACTION_SCHEMA
+    "light.dim_relative",
+    DimRelativeAction,
+    LIGHT_DIM_RELATIVE_ACTION_SCHEMA,
+    synchronous=True,
 )
 async def light_dim_relative_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
diff --git a/esphome/components/logger/__init__.py b/esphome/components/logger/__init__.py
index 264197c175..026b8aaf24 100644
--- a/esphome/components/logger/__init__.py
+++ b/esphome/components/logger/__init__.py
@@ -519,7 +519,9 @@ LOGGER_LOG_ACTION_SCHEMA = cv.All(
 )
 
 
-@automation.register_action(CONF_LOGGER_LOG, LambdaAction, LOGGER_LOG_ACTION_SCHEMA)
+@automation.register_action(
+    CONF_LOGGER_LOG, LambdaAction, LOGGER_LOG_ACTION_SCHEMA, synchronous=True
+)
 async def logger_log_action_to_code(config, action_id, template_arg, args):
     esp_log = LOG_LEVEL_TO_ESP_LOG[config[CONF_LEVEL]]
     args_ = [cg.RawExpression(str(x)) for x in config[CONF_ARGS]]
diff --git a/esphome/components/mipi_dsi/models/waveshare.py b/esphome/components/mipi_dsi/models/waveshare.py
index 69414065f1..c97a0bbd02 100644
--- a/esphome/components/mipi_dsi/models/waveshare.py
+++ b/esphome/components/mipi_dsi/models/waveshare.py
@@ -103,8 +103,6 @@ DriverChip(
         (0xE9, 0xC8, 0x10, 0x0A, 0x00, 0x00, 0x80, 0x81, 0x12, 0x31, 0x23, 0x4F, 0x86, 0xA0, 0x00, 0x47, 0x08, 0x00, 0x00, 0x0C, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0C, 0x00, 0x00, 0x00, 0x98, 0x02, 0x8B, 0xAF, 0x46, 0x02, 0x88, 0x88, 0x88, 0x88, 0x88, 0x98, 0x13, 0x8B, 0xAF, 0x57, 0x13, 0x88, 0x88, 0x88, 0x88, 0x88, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00),
         (0xEA, 0x97, 0x0C, 0x09, 0x09, 0x09, 0x78, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x9F, 0x31, 0x8B, 0xA8, 0x31, 0x75, 0x88, 0x88, 0x88, 0x88, 0x88, 0x9F, 0x20, 0x8B, 0xA8, 0x20, 0x64, 0x88, 0x88, 0x88, 0x88, 0x88, 0x23, 0x00, 0x00, 0x02, 0x71, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x40, 0x80, 0x81, 0x00, 0x00, 0x00, 0x00),
         (0xEF, 0xFF, 0xFF, 0x01),
-        (0x11, 0x00),
-        (0x29, 0x00),
     ],
 )
 
@@ -125,6 +123,7 @@ DriverChip(
     lane_bit_rate="900Mbps",
     no_transform=True,
     color_order="RGB",
+    reset_pin=33,
     initsequence=[
         (0x80, 0x8B),
         (0x81, 0x78),
diff --git a/esphome/components/mqtt/__init__.py b/esphome/components/mqtt/__init__.py
index 44e8836487..c25c472038 100644
--- a/esphome/components/mqtt/__init__.py
+++ b/esphome/components/mqtt/__init__.py
@@ -492,7 +492,7 @@ MQTT_PUBLISH_ACTION_SCHEMA = cv.Schema(
 
 
 @automation.register_action(
-    "mqtt.publish", MQTTPublishAction, MQTT_PUBLISH_ACTION_SCHEMA
+    "mqtt.publish", MQTTPublishAction, MQTT_PUBLISH_ACTION_SCHEMA, synchronous=True
 )
 async def mqtt_publish_action_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
@@ -521,7 +521,10 @@ MQTT_PUBLISH_JSON_ACTION_SCHEMA = cv.Schema(
 
 
 @automation.register_action(
-    "mqtt.publish_json", MQTTPublishJsonAction, MQTT_PUBLISH_JSON_ACTION_SCHEMA
+    "mqtt.publish_json",
+    MQTTPublishJsonAction,
+    MQTT_PUBLISH_JSON_ACTION_SCHEMA,
+    synchronous=True,
 )
 async def mqtt_publish_json_action_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
diff --git a/esphome/components/number/__init__.py b/esphome/components/number/__init__.py
index b23da7799f..2238f2c037 100644
--- a/esphome/components/number/__init__.py
+++ b/esphome/components/number/__init__.py
@@ -240,6 +240,23 @@ def number_schema(
     return _NUMBER_SCHEMA.extend(schema)
 
 
+@coroutine_with_priority(CoroPriority.AUTOMATION)
+async def _build_number_automations(var, config):
+    for conf in config.get(CONF_ON_VALUE, []):
+        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
+        await automation.build_automation(trigger, [(float, "x")], conf)
+    for conf in config.get(CONF_ON_VALUE_RANGE, []):
+        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
+        await cg.register_component(trigger, conf)
+        if CONF_ABOVE in conf:
+            template_ = await cg.templatable(conf[CONF_ABOVE], [(float, "x")], float)
+            cg.add(trigger.set_min(template_))
+        if CONF_BELOW in conf:
+            template_ = await cg.templatable(conf[CONF_BELOW], [(float, "x")], float)
+            cg.add(trigger.set_max(template_))
+        await automation.build_automation(trigger, [(float, "x")], conf)
+
+
 async def setup_number_core_(
     var, config, *, min_value: float, max_value: float, step: float
 ):
@@ -254,19 +271,7 @@ async def setup_number_core_(
     if config[CONF_MODE] != NumberMode.NUMBER_MODE_AUTO:
         cg.add(var.traits.set_mode(config[CONF_MODE]))
 
-    for conf in config.get(CONF_ON_VALUE, []):
-        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
-        await automation.build_automation(trigger, [(float, "x")], conf)
-    for conf in config.get(CONF_ON_VALUE_RANGE, []):
-        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
-        await cg.register_component(trigger, conf)
-        if CONF_ABOVE in conf:
-            template_ = await cg.templatable(conf[CONF_ABOVE], [(float, "x")], float)
-            cg.add(trigger.set_min(template_))
-        if CONF_BELOW in conf:
-            template_ = await cg.templatable(conf[CONF_BELOW], [(float, "x")], float)
-            cg.add(trigger.set_max(template_))
-        await automation.build_automation(trigger, [(float, "x")], conf)
+    CORE.add_job(_build_number_automations, var, config)
 
     if (unit_of_measurement := config.get(CONF_UNIT_OF_MEASUREMENT)) is not None:
         cg.add(var.traits.set_unit_of_measurement(unit_of_measurement))
@@ -347,6 +352,7 @@ OPERATION_BASE_SCHEMA = cv.Schema(
             cv.Required(CONF_VALUE): cv.templatable(cv.float_),
         }
     ),
+    synchronous=True,
 )
 async def number_set_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
@@ -369,6 +375,7 @@ async def number_set_to_code(config, action_id, template_arg, args):
             }
         )
     ),
+    synchronous=True,
 )
 @automation.register_action(
     "number.decrement",
@@ -383,6 +390,7 @@ async def number_set_to_code(config, action_id, template_arg, args):
             }
         )
     ),
+    synchronous=True,
 )
 @automation.register_action(
     "number.to_min",
@@ -396,6 +404,7 @@ async def number_set_to_code(config, action_id, template_arg, args):
             }
         )
     ),
+    synchronous=True,
 )
 @automation.register_action(
     "number.to_max",
@@ -409,6 +418,7 @@ async def number_set_to_code(config, action_id, template_arg, args):
             }
         )
     ),
+    synchronous=True,
 )
 @automation.register_action(
     "number.operation",
@@ -421,6 +431,7 @@ async def number_set_to_code(config, action_id, template_arg, args):
             cv.Optional(CONF_CYCLE, default=True): cv.templatable(cv.boolean),
         }
     ),
+    synchronous=True,
 )
 async def number_to_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
diff --git a/esphome/components/output/__init__.py b/esphome/components/output/__init__.py
index bde106b085..a4c960927b 100644
--- a/esphome/components/output/__init__.py
+++ b/esphome/components/output/__init__.py
@@ -74,14 +74,16 @@ BINARY_OUTPUT_ACTION_SCHEMA = maybe_simple_id(
 )
 
 
-@automation.register_action("output.turn_on", TurnOnAction, BINARY_OUTPUT_ACTION_SCHEMA)
+@automation.register_action(
+    "output.turn_on", TurnOnAction, BINARY_OUTPUT_ACTION_SCHEMA, synchronous=True
+)
 async def output_turn_on_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
     return cg.new_Pvariable(action_id, template_arg, paren)
 
 
 @automation.register_action(
-    "output.turn_off", TurnOffAction, BINARY_OUTPUT_ACTION_SCHEMA
+    "output.turn_off", TurnOffAction, BINARY_OUTPUT_ACTION_SCHEMA, synchronous=True
 )
 async def output_turn_off_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
@@ -97,6 +99,7 @@ async def output_turn_off_to_code(config, action_id, template_arg, args):
             cv.Required(CONF_LEVEL): cv.templatable(cv.percentage),
         }
     ),
+    synchronous=True,
 )
 async def output_set_level_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
diff --git a/esphome/components/script/__init__.py b/esphome/components/script/__init__.py
index 8d69981db0..369cefad91 100644
--- a/esphome/components/script/__init__.py
+++ b/esphome/components/script/__init__.py
@@ -160,6 +160,7 @@ async def to_code(config):
             cv.Optional(validate_parameter_name): cv.templatable(cv.valid),
         },
     ),
+    synchronous=True,
 )
 async def script_execute_action_to_code(config, action_id, template_arg, args):
     def convert(type: str):
@@ -208,6 +209,7 @@ async def script_execute_action_to_code(config, action_id, template_arg, args):
     "script.stop",
     ScriptStopAction,
     maybe_simple_id({cv.Required(CONF_ID): cv.use_id(Script)}),
+    synchronous=True,
 )
 async def script_stop_action_to_code(config, action_id, template_arg, args):
     full_id, paren = await cg.get_variable_with_full_id(config[CONF_ID])
diff --git a/esphome/components/select/__init__.py b/esphome/components/select/__init__.py
index 84ad591ba1..c114b140a9 100644
--- a/esphome/components/select/__init__.py
+++ b/esphome/components/select/__init__.py
@@ -145,6 +145,7 @@ OPERATION_BASE_SCHEMA = cv.Schema(
             cv.Required(CONF_OPTION): cv.templatable(cv.string_strict),
         }
     ),
+    synchronous=True,
 )
 async def select_set_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
@@ -162,6 +163,7 @@ async def select_set_to_code(config, action_id, template_arg, args):
             cv.Required(CONF_INDEX): cv.templatable(cv.positive_int),
         }
     ),
+    synchronous=True,
 )
 async def select_set_index_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
@@ -217,6 +219,7 @@ async def select_is_to_code(config, condition_id, template_arg, args):
             cv.Optional(CONF_CYCLE, default=True): cv.templatable(cv.boolean),
         }
     ),
+    synchronous=True,
 )
 @automation.register_action(
     "select.next",
@@ -229,6 +232,7 @@ async def select_is_to_code(config, condition_id, template_arg, args):
             }
         )
     ),
+    synchronous=True,
 )
 @automation.register_action(
     "select.previous",
@@ -243,6 +247,7 @@ async def select_is_to_code(config, condition_id, template_arg, args):
             }
         )
     ),
+    synchronous=True,
 )
 @automation.register_action(
     "select.first",
@@ -254,6 +259,7 @@ async def select_is_to_code(config, condition_id, template_arg, args):
             }
         )
     ),
+    synchronous=True,
 )
 @automation.register_action(
     "select.last",
@@ -265,6 +271,7 @@ async def select_is_to_code(config, condition_id, template_arg, args):
             }
         )
     ),
+    synchronous=True,
 )
 async def select_operation_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
diff --git a/esphome/components/sensor/__init__.py b/esphome/components/sensor/__init__.py
index 770c044efb..338aaae0b5 100644
--- a/esphome/components/sensor/__init__.py
+++ b/esphome/components/sensor/__init__.py
@@ -888,6 +888,26 @@ async def build_filters(config):
     return await cg.build_registry_list(FILTER_REGISTRY, config)
 
 
+@coroutine_with_priority(CoroPriority.AUTOMATION)
+async def _build_sensor_automations(var, config):
+    for conf in config.get(CONF_ON_VALUE, []):
+        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
+        await automation.build_automation(trigger, [(float, "x")], conf)
+    for conf in config.get(CONF_ON_RAW_VALUE, []):
+        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
+        await automation.build_automation(trigger, [(float, "x")], conf)
+    for conf in config.get(CONF_ON_VALUE_RANGE, []):
+        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
+        await cg.register_component(trigger, conf)
+        if (above := conf.get(CONF_ABOVE)) is not None:
+            template_ = await cg.templatable(above, [(float, "x")], float)
+            cg.add(trigger.set_min(template_))
+        if (below := conf.get(CONF_BELOW)) is not None:
+            template_ = await cg.templatable(below, [(float, "x")], float)
+            cg.add(trigger.set_max(template_))
+        await automation.build_automation(trigger, [(float, "x")], conf)
+
+
 async def setup_sensor_core_(var, config):
     await setup_entity(var, config, "sensor")
 
@@ -907,22 +927,7 @@ async def setup_sensor_core_(var, config):
         filters = await build_filters(config[CONF_FILTERS])
         cg.add(var.set_filters(filters))
 
-    for conf in config.get(CONF_ON_VALUE, []):
-        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
-        await automation.build_automation(trigger, [(float, "x")], conf)
-    for conf in config.get(CONF_ON_RAW_VALUE, []):
-        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
-        await automation.build_automation(trigger, [(float, "x")], conf)
-    for conf in config.get(CONF_ON_VALUE_RANGE, []):
-        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
-        await cg.register_component(trigger, conf)
-        if (above := conf.get(CONF_ABOVE)) is not None:
-            template_ = await cg.templatable(above, [(float, "x")], float)
-            cg.add(trigger.set_min(template_))
-        if (below := conf.get(CONF_BELOW)) is not None:
-            template_ = await cg.templatable(below, [(float, "x")], float)
-            cg.add(trigger.set_max(template_))
-        await automation.build_automation(trigger, [(float, "x")], conf)
+    CORE.add_job(_build_sensor_automations, var, config)
 
     if (mqtt_id := config.get(CONF_MQTT_ID)) is not None:
         mqtt_ = cg.new_Pvariable(mqtt_id, var)
diff --git a/esphome/components/switch/__init__.py b/esphome/components/switch/__init__.py
index 7424d7c92f..6f1be7d53d 100644
--- a/esphome/components/switch/__init__.py
+++ b/esphome/components/switch/__init__.py
@@ -141,11 +141,8 @@ def switch_schema(
     return _SWITCH_SCHEMA.extend(schema)
 
 
-async def setup_switch_core_(var, config):
-    await setup_entity(var, config, "switch")
-
-    if (inverted := config.get(CONF_INVERTED)) is not None:
-        cg.add(var.set_inverted(inverted))
+@coroutine_with_priority(CoroPriority.AUTOMATION)
+async def _build_switch_automations(var, config):
     for conf in config.get(CONF_ON_STATE, []):
         trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
         await automation.build_automation(trigger, [(bool, "x")], conf)
@@ -156,6 +153,15 @@ async def setup_switch_core_(var, config):
         trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
         await automation.build_automation(trigger, [], conf)
 
+
+async def setup_switch_core_(var, config):
+    await setup_entity(var, config, "switch")
+
+    if (inverted := config.get(CONF_INVERTED)) is not None:
+        cg.add(var.set_inverted(inverted))
+
+    CORE.add_job(_build_switch_automations, var, config)
+
     if (mqtt_id := config.get(CONF_MQTT_ID)) is not None:
         mqtt_ = cg.new_Pvariable(mqtt_id, var)
         await mqtt.register_mqtt_component(mqtt_, config)
@@ -198,7 +204,7 @@ SWITCH_CONTROL_ACTION_SCHEMA = automation.maybe_simple_id(
 
 
 @automation.register_action(
-    "switch.control", ControlAction, SWITCH_CONTROL_ACTION_SCHEMA
+    "switch.control", ControlAction, SWITCH_CONTROL_ACTION_SCHEMA, synchronous=True
 )
 async def switch_control_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
@@ -208,9 +214,15 @@ async def switch_control_to_code(config, action_id, template_arg, args):
     return var
 
 
-@automation.register_action("switch.toggle", ToggleAction, SWITCH_ACTION_SCHEMA)
-@automation.register_action("switch.turn_off", TurnOffAction, SWITCH_ACTION_SCHEMA)
-@automation.register_action("switch.turn_on", TurnOnAction, SWITCH_ACTION_SCHEMA)
+@automation.register_action(
+    "switch.toggle", ToggleAction, SWITCH_ACTION_SCHEMA, synchronous=True
+)
+@automation.register_action(
+    "switch.turn_off", TurnOffAction, SWITCH_ACTION_SCHEMA, synchronous=True
+)
+@automation.register_action(
+    "switch.turn_on", TurnOnAction, SWITCH_ACTION_SCHEMA, synchronous=True
+)
 async def switch_toggle_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
     return cg.new_Pvariable(action_id, template_arg, paren)
diff --git a/esphome/components/text/__init__.py b/esphome/components/text/__init__.py
index 9ceea0dfdf..61f7119cad 100644
--- a/esphome/components/text/__init__.py
+++ b/esphome/components/text/__init__.py
@@ -164,6 +164,7 @@ OPERATION_BASE_SCHEMA = cv.Schema(
             cv.Required(CONF_VALUE): cv.templatable(cv.string_strict),
         }
     ),
+    synchronous=True,
 )
 async def text_set_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
diff --git a/esphome/components/text_sensor/__init__.py b/esphome/components/text_sensor/__init__.py
index 2e8edb43c9..2edf202cd2 100644
--- a/esphome/components/text_sensor/__init__.py
+++ b/esphome/components/text_sensor/__init__.py
@@ -197,6 +197,17 @@ async def build_filters(config):
     return await cg.build_registry_list(FILTER_REGISTRY, config)
 
 
+@coroutine_with_priority(CoroPriority.AUTOMATION)
+async def _build_text_sensor_automations(var, config):
+    for conf in config.get(CONF_ON_VALUE, []):
+        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
+        await automation.build_automation(trigger, [(cg.std_string, "x")], conf)
+
+    for conf in config.get(CONF_ON_RAW_VALUE, []):
+        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
+        await automation.build_automation(trigger, [(cg.std_string, "x")], conf)
+
+
 async def setup_text_sensor_core_(var, config):
     await setup_entity(var, config, "text_sensor")
 
@@ -208,13 +219,7 @@ async def setup_text_sensor_core_(var, config):
         filters = await build_filters(config[CONF_FILTERS])
         cg.add(var.set_filters(filters))
 
-    for conf in config.get(CONF_ON_VALUE, []):
-        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
-        await automation.build_automation(trigger, [(cg.std_string, "x")], conf)
-
-    for conf in config.get(CONF_ON_RAW_VALUE, []):
-        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
-        await automation.build_automation(trigger, [(cg.std_string, "x")], conf)
+    CORE.add_job(_build_text_sensor_automations, var, config)
 
     if (mqtt_id := config.get(CONF_MQTT_ID)) is not None:
         mqtt_ = cg.new_Pvariable(mqtt_id, var)
diff --git a/esphome/components/time/__init__.py b/esphome/components/time/__init__.py
index a20d79b857..7ffa408db9 100644
--- a/esphome/components/time/__init__.py
+++ b/esphome/components/time/__init__.py
@@ -1,6 +1,10 @@
 from importlib import resources
 import logging
 
+from aioesphomeapi.posix_tz import (
+    DSTRuleType as PyDSTRuleType,
+    parse_posix_tz as parse_posix_tz_python,
+)
 import tzlocal
 
 from esphome import automation
@@ -39,6 +43,19 @@ CronTrigger = time_ns.class_("CronTrigger", automation.Trigger.template(), cg.Co
 SyncTrigger = time_ns.class_("SyncTrigger", automation.Trigger.template(), cg.Component)
 TimeHasTimeCondition = time_ns.class_("TimeHasTimeCondition", Condition)
 
+# C++ types for pre-parsed timezone struct generation
+DSTRuleType_cpp = time_ns.enum("DSTRuleType", is_class=True)
+DSTRule_cpp = time_ns.struct("DSTRule")
+ParsedTimezone_cpp = time_ns.struct("ParsedTimezone")
+
+# Map Python DSTRuleType enum values to C++ enum expressions
+_DST_RULE_TYPE_MAP = {
+    PyDSTRuleType.NONE: DSTRuleType_cpp.NONE,
+    PyDSTRuleType.MONTH_WEEK_DAY: DSTRuleType_cpp.MONTH_WEEK_DAY,
+    PyDSTRuleType.JULIAN_NO_LEAP: DSTRuleType_cpp.JULIAN_NO_LEAP,
+    PyDSTRuleType.DAY_OF_YEAR: DSTRuleType_cpp.DAY_OF_YEAR,
+}
+
 
 def _load_tzdata(iana_key: str) -> bytes | None:
     # From https://tzdata.readthedocs.io/en/latest/#examples
@@ -260,11 +277,17 @@ def validate_tz(value: str) -> str:
     value = cv.string_strict(value)
 
     tzfile = _load_tzdata(value)
-    if tzfile is None:
-        # Not a IANA key, probably a TZ string
-        return value
+    if tzfile is not None:
+        value = _extract_tz_string(tzfile)
 
-    return _extract_tz_string(tzfile)
+    # Validate that the POSIX TZ string is parseable (skip empty strings)
+    if value:
+        try:
+            parse_posix_tz_python(value)
+        except ValueError as e:
+            raise cv.Invalid(f"Invalid POSIX timezone string '{value}': {e}") from e
+
+    return value
 
 
 TIME_SCHEMA = cv.Schema(
@@ -305,11 +328,46 @@ TIME_SCHEMA = cv.Schema(
 ).extend(cv.polling_component_schema("15min"))
 
 
+def _emit_dst_rule_fields(prefix, rule):
+    """Emit field-by-field assignments for a DSTRule to avoid rodata struct blob."""
+    cg.add(cg.RawExpression(f"{prefix}.time_seconds = {rule.time_seconds}"))
+    cg.add(cg.RawExpression(f"{prefix}.day = {rule.day}"))
+    cg.add(cg.RawExpression(f"{prefix}.type = {_DST_RULE_TYPE_MAP[rule.type]}"))
+    cg.add(cg.RawExpression(f"{prefix}.month = {rule.month}"))
+    cg.add(cg.RawExpression(f"{prefix}.week = {rule.week}"))
+    cg.add(cg.RawExpression(f"{prefix}.day_of_week = {rule.day_of_week}"))
+
+
+def _emit_parsed_timezone_fields(parsed):
+    """Emit field-by-field assignments for a local ParsedTimezone, then set_global_tz().
+
+    Uses individual assignments on a stack variable instead of a struct initializer
+    to keep constants as immediate operands in instructions (.irom0.text/flash)
+    rather than a const blob in .rodata (which maps to RAM on ESP8266).
+    Wrapped in a scope block to allow multiple time platforms in the same build.
+    """
+    cg.add(cg.RawStatement("{"))
+    cg.add(cg.RawExpression("time::ParsedTimezone tz{}"))
+    cg.add(cg.RawExpression(f"tz.std_offset_seconds = {parsed.std_offset_seconds}"))
+    cg.add(cg.RawExpression(f"tz.dst_offset_seconds = {parsed.dst_offset_seconds}"))
+    _emit_dst_rule_fields("tz.dst_start", parsed.dst_start)
+    _emit_dst_rule_fields("tz.dst_end", parsed.dst_end)
+    cg.add(time_ns.set_global_tz(cg.RawExpression("tz")))
+    cg.add(cg.RawStatement("}"))
+
+
 async def setup_time_core_(time_var, config):
     if timezone := config.get(CONF_TIMEZONE):
-        cg.add(time_var.set_timezone(timezone))
         cg.add_define("USE_TIME_TIMEZONE")
 
+        if CORE.is_host:
+            # Host platform needs setenv("TZ")/tzset() for libc compatibility
+            cg.add(time_var.set_timezone(timezone))
+        else:
+            # Embedded: pre-parse at codegen time, emit struct directly
+            parsed = parse_posix_tz_python(timezone)
+            _emit_parsed_timezone_fields(parsed)
+
     for conf in config.get(CONF_ON_TIME, []):
         trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], time_var)
 
diff --git a/esphome/components/uart/__init__.py b/esphome/components/uart/__init__.py
index 31e37a06e0..69db4b44aa 100644
--- a/esphome/components/uart/__init__.py
+++ b/esphome/components/uart/__init__.py
@@ -1,4 +1,3 @@
-from dataclasses import dataclass
 from logging import getLogger
 import math
 import re
@@ -12,6 +11,7 @@ from esphome.const import (
     CONF_BAUD_RATE,
     CONF_BYTES,
     CONF_DATA,
+    CONF_DATA_BITS,
     CONF_DEBUG,
     CONF_DELIMITER,
     CONF_DIRECTION,
@@ -21,10 +21,12 @@ from esphome.const import (
     CONF_ID,
     CONF_LAMBDA,
     CONF_NUMBER,
+    CONF_PARITY,
     CONF_PORT,
     CONF_RX_BUFFER_SIZE,
     CONF_RX_PIN,
     CONF_SEQUENCE,
+    CONF_STOP_BITS,
     CONF_TIMEOUT,
     CONF_TRIGGER_ID,
     CONF_TX_PIN,
@@ -114,38 +116,6 @@ MULTI_CONF = True
 MULTI_CONF_NO_DEFAULT = True
 
 
-@dataclass
-class UARTData:
-    """State data for UART component configuration generation."""
-
-    wake_loop_on_rx: bool = False
-
-
-def _get_data() -> UARTData:
-    """Get UART component data from CORE.data."""
-    if DOMAIN not in CORE.data:
-        CORE.data[DOMAIN] = UARTData()
-    return CORE.data[DOMAIN]
-
-
-def request_wake_loop_on_rx() -> None:
-    """Request that the UART wake the main loop when data is received.
-
-    Components that need low-latency notification of incoming UART data
-    should call this function during their code generation.
-    This enables the RX event task which wakes the main loop when data arrives.
-    """
-    data = _get_data()
-    if not data.wake_loop_on_rx:
-        data.wake_loop_on_rx = True
-
-        # UART RX event task uses wake_loop_threadsafe() to notify the main loop
-        # Automatically enable the socket wake infrastructure when RX wake is requested
-        from esphome.components import socket
-
-        socket.require_wake_loop_threadsafe()
-
-
 def validate_raw_data(value):
     if isinstance(value, str):
         return value.encode("utf-8")
@@ -215,9 +185,6 @@ UART_PARITY_OPTIONS = {
     "ODD": UARTParityOptions.UART_CONFIG_PARITY_ODD,
 }
 
-CONF_STOP_BITS = "stop_bits"
-CONF_DATA_BITS = "data_bits"
-CONF_PARITY = "parity"
 CONF_RX_FULL_THRESHOLD = "rx_full_threshold"
 CONF_RX_TIMEOUT = "rx_timeout"
 
@@ -542,7 +509,14 @@ async def uart_write_to_code(config, action_id, template_arg, args):
 @coroutine_with_priority(CoroPriority.FINAL)
 async def final_step():
     """Final code generation step to configure optional UART features."""
-    if _get_data().wake_loop_on_rx:
+    if CORE.is_esp32 and CORE.has_networking:
+        # Wake-on-RX is essentially free on ESP32 (just an ISR function pointer
+        # registration) — enable by default to reduce RX buffer overflow risk
+        # by waking the main loop immediately when data arrives.
+        # Requires networking for the wake_loop_isrsafe() infrastructure.
+        from esphome.components import socket
+
+        socket.require_wake_loop_threadsafe()
         cg.add_define("USE_UART_WAKE_LOOP_ON_RX")
 
 
diff --git a/esphome/components/uart/uart_component_esp_idf.cpp b/esphome/components/uart/uart_component_esp_idf.cpp
index ea7a09fee6..631db1e5c7 100644
--- a/esphome/components/uart/uart_component_esp_idf.cpp
+++ b/esphome/components/uart/uart_component_esp_idf.cpp
@@ -2,14 +2,16 @@
 
 #include "uart_component_esp_idf.h"
 #include <cinttypes>
-#include "esphome/core/application.h"
 #include "esphome/core/defines.h"
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 #include "esphome/core/gpio.h"
 #include "driver/gpio.h"
 #include "soc/gpio_num.h"
-#include "soc/uart_pins.h"
+
+#ifdef USE_UART_WAKE_LOOP_ON_RX
+#include "esphome/core/application.h"
+#endif
 
 #ifdef USE_LOGGER
 #include "esphome/components/logger/logger.h"
@@ -19,13 +21,6 @@ namespace esphome::uart {
 
 static const char *const TAG = "uart.idf";
 
-/// Check if a pin number matches one of the default UART0 GPIO pins.
-/// These pins may have residual state from the boot console that requires
-/// explicit reset before UART reconfiguration (ESP-IDF issue #17459).
-static constexpr bool is_default_uart0_pin(int8_t pin_num) {
-  return pin_num == U0TXD_GPIO_NUM || pin_num == U0RXD_GPIO_NUM;
-}
-
 uart_config_t IDFUARTComponent::get_config_() {
   uart_parity_t parity = UART_PARITY_DISABLE;
   if (this->parity_ == UART_CONFIG_PARITY_EVEN) {
@@ -115,12 +110,6 @@ void IDFUARTComponent::load_settings(bool dump_config) {
   esp_err_t err;
 
   if (uart_is_driver_installed(this->uart_num_)) {
-#ifdef USE_UART_WAKE_LOOP_ON_RX
-    if (this->rx_event_task_handle_ != nullptr) {
-      vTaskDelete(this->rx_event_task_handle_);
-      this->rx_event_task_handle_ = nullptr;
-    }
-#endif
     err = uart_driver_delete(this->uart_num_);
     if (err != ESP_OK) {
       ESP_LOGW(TAG, "uart_driver_delete failed: %s", esp_err_to_name(err));
@@ -128,20 +117,13 @@ void IDFUARTComponent::load_settings(bool dump_config) {
       return;
     }
   }
-#ifdef USE_UART_WAKE_LOOP_ON_RX
-  constexpr int event_queue_size = 20;
-  QueueHandle_t *event_queue_ptr = &this->uart_event_queue_;
-#else
-  constexpr int event_queue_size = 0;
-  QueueHandle_t *event_queue_ptr = nullptr;
-#endif
   err = uart_driver_install(this->uart_num_,        // UART number
                             this->rx_buffer_size_,  // RX ring buffer size
                             0,  // TX ring buffer size. If zero, driver will not use a TX buffer and TX function will
                                 // block task until all data has been sent out
-                            event_queue_size,  // event queue size/depth
-                            event_queue_ptr,   // event queue
-                            0                  // Flags used to allocate the interrupt
+                            0,  // event queue size/depth
+                            nullptr,  // event queue
+                            0         // Flags used to allocate the interrupt
   );
   if (err != ESP_OK) {
     ESP_LOGW(TAG, "uart_driver_install failed: %s", esp_err_to_name(err));
@@ -149,34 +131,12 @@ void IDFUARTComponent::load_settings(bool dump_config) {
     return;
   }
 
-  int8_t tx = this->tx_pin_ != nullptr ? this->tx_pin_->get_pin() : -1;
-  int8_t rx = this->rx_pin_ != nullptr ? this->rx_pin_->get_pin() : -1;
-  int8_t flow_control = this->flow_control_pin_ != nullptr ? this->flow_control_pin_->get_pin() : -1;
-
-  // Workaround for ESP-IDF issue: https://github.com/espressif/esp-idf/issues/17459
-  // Commit 9ed617fb17 removed gpio_func_sel() calls from uart_set_pin(), which breaks
-  // UART on default UART0 pins that may have residual state from boot console.
-  // Reset these pins before configuring UART to ensure they're in a clean state.
-  if (is_default_uart0_pin(tx)) {
-    gpio_reset_pin(static_cast<gpio_num_t>(tx));
-  }
-  if (is_default_uart0_pin(rx)) {
-    gpio_reset_pin(static_cast<gpio_num_t>(rx));
-  }
-
-  // Setup pins after reset to configure GPIO direction and pull resistors.
-  // For UART0 default pins, setup() must always be called because gpio_reset_pin()
-  // above sets GPIO_MODE_DISABLE which disables the input buffer. Without setup(),
-  // uart_set_pin() on ESP-IDF 5.4.2+ does not re-enable the input buffer for
-  // IOMUX-connected pins, so the RX pin cannot receive data (see issue #10132).
-  // For other pins, only call setup() if pull or open-drain flags are set to avoid
-  // disturbing the default pin state which breaks some external components (#11823).
   auto setup_pin_if_needed = [](InternalGPIOPin *pin) {
     if (!pin) {
       return;
     }
     const auto mask = gpio::Flags::FLAG_OPEN_DRAIN | gpio::Flags::FLAG_PULLUP | gpio::Flags::FLAG_PULLDOWN;
-    if (is_default_uart0_pin(pin->get_pin()) || (pin->get_flags() & mask) != gpio::Flags::FLAG_NONE) {
+    if ((pin->get_flags() & mask) != gpio::Flags::FLAG_NONE) {
       pin->setup();
     }
   };
@@ -186,6 +146,10 @@ void IDFUARTComponent::load_settings(bool dump_config) {
     setup_pin_if_needed(this->tx_pin_);
   }
 
+  int8_t tx = this->tx_pin_ != nullptr ? this->tx_pin_->get_pin() : -1;
+  int8_t rx = this->rx_pin_ != nullptr ? this->rx_pin_->get_pin() : -1;
+  int8_t flow_control = this->flow_control_pin_ != nullptr ? this->flow_control_pin_->get_pin() : -1;
+
   uint32_t invert = 0;
   if (this->tx_pin_ != nullptr && this->tx_pin_->is_inverted()) {
     invert |= UART_SIGNAL_TXD_INV;
@@ -239,8 +203,10 @@ void IDFUARTComponent::load_settings(bool dump_config) {
   }
 
 #ifdef USE_UART_WAKE_LOOP_ON_RX
-  // Start the RX event task to enable low-latency data notifications
-  this->start_rx_event_task_();
+  // Register ISR callback to wake the main loop when UART data arrives.
+  // The callback runs in ISR context and uses vTaskNotifyGiveFromISR() to
+  // wake the main loop task directly — no queue or FreeRTOS task needed.
+  uart_set_select_notif_callback(this->uart_num_, IDFUARTComponent::uart_rx_isr_callback);
 #endif  // USE_UART_WAKE_LOOP_ON_RX
 
   if (dump_config) {
@@ -371,71 +337,12 @@ void IDFUARTComponent::flush() {
 void IDFUARTComponent::check_logger_conflict() {}
 
 #ifdef USE_UART_WAKE_LOOP_ON_RX
-void IDFUARTComponent::start_rx_event_task_() {
-  // Create FreeRTOS task to monitor UART events
-  BaseType_t result = xTaskCreate(rx_event_task_func,    // Task function
-                                  "uart_rx_evt",         // Task name (max 16 chars)
-                                  2240,                  // Stack size in bytes (~2.2KB); increase if needed for logging
-                                  this,                  // Task parameter (this pointer)
-                                  tskIDLE_PRIORITY + 1,  // Priority (low, just above idle)
-                                  &this->rx_event_task_handle_  // Task handle
-  );
-
-  if (result != pdPASS) {
-    ESP_LOGE(TAG, "Failed to create RX event task");
-    return;
-  }
-
-  ESP_LOGV(TAG, "RX event task started");
-}
-
-// FreeRTOS task that relays UART ISR events to the main loop.
-// This task exists because wake_loop_threadsafe() is not ISR-safe (it uses a
-// UDP loopback socket), so we need a task as an ISR-to-main-loop trampoline.
-// IMPORTANT: This task must NOT call any UART wrapper methods (read_array,
-// write_array, peek_byte, etc.) or touch has_peek_/peek_byte_ — all reading
-// is done by the main loop. This task only reads from the event queue and
-// calls App.wake_loop_threadsafe().
-void IDFUARTComponent::rx_event_task_func(void *param) {
-  auto *self = static_cast<IDFUARTComponent *>(param);
-  uart_event_t event;
-
-  ESP_LOGV(TAG, "RX event task running");
-
-  // Run forever - task lifecycle matches component lifecycle
-  while (true) {
-    // Wait for UART events (blocks efficiently)
-    if (xQueueReceive(self->uart_event_queue_, &event, portMAX_DELAY) == pdTRUE) {
-      switch (event.type) {
-        case UART_DATA:
-          // Data available in UART RX buffer - wake the main loop
-          ESP_LOGVV(TAG, "Data event: %d bytes", event.size);
-#if defined(USE_SOCKET_SELECT_SUPPORT) && defined(USE_WAKE_LOOP_THREADSAFE)
-          App.wake_loop_threadsafe();
-#endif
-          break;
-
-        case UART_FIFO_OVF:
-        case UART_BUFFER_FULL:
-          // Don't call uart_flush_input() here — this task does not own the read side.
-          // ESP-IDF examples flush on overflow because the same task handles both events
-          // and reads, so flush and read are serialized. Here, reads happen on the main
-          // loop, so flushing from this task races with read_array() and can destroy data
-          // mid-read. The driver self-heals without an explicit flush: uart_read_bytes()
-          // calls uart_check_buf_full() after each chunk, which moves stashed FIFO bytes
-          // into the ring buffer and re-enables RX interrupts once space is freed.
-          ESP_LOGW(TAG, "FIFO overflow or ring buffer full");
-#if defined(USE_SOCKET_SELECT_SUPPORT) && defined(USE_WAKE_LOOP_THREADSAFE)
-          App.wake_loop_threadsafe();
-#endif
-          break;
-
-        default:
-          // Ignore other event types
-          ESP_LOGVV(TAG, "Event type: %d", event.type);
-          break;
-      }
-    }
+// ISR callback invoked by the ESP-IDF UART driver when data arrives.
+// Wakes the main loop directly via vTaskNotifyGiveFromISR() — no queue or task needed.
+void IRAM_ATTR IDFUARTComponent::uart_rx_isr_callback(uart_port_t uart_num, uart_select_notif_t uart_select_notif,
+                                                      BaseType_t *task_woken) {
+  if (uart_select_notif == UART_SELECT_READ_NOTIF) {
+    Application::wake_loop_isrsafe(task_woken);
   }
 }
 #endif  // USE_UART_WAKE_LOOP_ON_RX
diff --git a/esphome/components/uart/uart_component_esp_idf.h b/esphome/components/uart/uart_component_esp_idf.h
index 1517eab509..631bf54cd5 100644
--- a/esphome/components/uart/uart_component_esp_idf.h
+++ b/esphome/components/uart/uart_component_esp_idf.h
@@ -5,6 +5,9 @@
 #include <driver/uart.h>
 #include "esphome/core/component.h"
 #include "uart_component.h"
+#ifdef USE_UART_WAKE_LOOP_ON_RX
+#include <driver/uart_select.h>
+#endif
 
 namespace esphome::uart {
 
@@ -12,9 +15,7 @@ namespace esphome::uart {
 ///
 /// Thread safety: All public methods must only be called from the main loop.
 /// The ESP-IDF UART driver API does not guarantee thread safety, and ESPHome's
-/// peek byte state (has_peek_/peek_byte_) is not synchronized. The rx_event_task
-/// (when enabled) must not call any of these methods — it communicates with the
-/// main loop exclusively via App.wake_loop_threadsafe().
+/// peek byte state (has_peek_/peek_byte_) is not synchronized.
 class IDFUARTComponent : public UARTComponent, public Component {
  public:
   void setup() override;
@@ -33,9 +34,6 @@ class IDFUARTComponent : public UARTComponent, public Component {
   void flush() override;
 
   uint8_t get_hw_serial_number() { return this->uart_num_; }
-#ifdef USE_UART_WAKE_LOOP_ON_RX
-  QueueHandle_t *get_uart_event_queue() { return &this->uart_event_queue_; }
-#endif
 
   /**
    * Load the UART with the current settings.
@@ -61,15 +59,8 @@ class IDFUARTComponent : public UARTComponent, public Component {
   uint8_t peek_byte_;
 
 #ifdef USE_UART_WAKE_LOOP_ON_RX
-  // RX notification support — runs on a separate FreeRTOS task.
-  // IMPORTANT: rx_event_task_func must NOT call any UART wrapper methods (read_array,
-  // write_array, etc.) or touch has_peek_/peek_byte_. It must only read from the
-  // event queue and call App.wake_loop_threadsafe().
-  void start_rx_event_task_();
-  static void rx_event_task_func(void *param);
-
-  QueueHandle_t uart_event_queue_;
-  TaskHandle_t rx_event_task_handle_{nullptr};
+  // ISR callback for UART RX data notification — wakes the main loop directly.
+  static void uart_rx_isr_callback(uart_port_t uart_num, uart_select_notif_t uart_select_notif, BaseType_t *task_woken);
 #endif  // USE_UART_WAKE_LOOP_ON_RX
 };
 
diff --git a/esphome/components/usb_uart/__init__.py b/esphome/components/usb_uart/__init__.py
index d9bb58ae3a..cc69c0cb5a 100644
--- a/esphome/components/usb_uart/__init__.py
+++ b/esphome/components/usb_uart/__init__.py
@@ -1,20 +1,18 @@
 import esphome.codegen as cg
 from esphome.components import socket
-from esphome.components.uart import (
-    CONF_DATA_BITS,
-    CONF_PARITY,
-    CONF_STOP_BITS,
-    UARTComponent,
-)
+from esphome.components.uart import UARTComponent
 from esphome.components.usb_host import register_usb_client, usb_device_schema
 import esphome.config_validation as cv
 from esphome.const import (
     CONF_BAUD_RATE,
     CONF_BUFFER_SIZE,
     CONF_CHANNELS,
+    CONF_DATA_BITS,
     CONF_DEBUG,
     CONF_DUMMY_RECEIVER,
     CONF_ID,
+    CONF_PARITY,
+    CONF_STOP_BITS,
 )
 from esphome.cpp_types import Component
 
diff --git a/esphome/components/weikai/__init__.py b/esphome/components/weikai/__init__.py
index 796423438e..66cd4ce12a 100644
--- a/esphome/components/weikai/__init__.py
+++ b/esphome/components/weikai/__init__.py
@@ -4,21 +4,21 @@ import esphome.config_validation as cv
 from esphome.const import (
     CONF_BAUD_RATE,
     CONF_CHANNEL,
+    CONF_DATA_BITS,
     CONF_ID,
     CONF_INPUT,
     CONF_INVERTED,
     CONF_MODE,
     CONF_NUMBER,
     CONF_OUTPUT,
+    CONF_PARITY,
+    CONF_STOP_BITS,
 )
 
 CODEOWNERS = ["@DrCoolZic"]
 AUTO_LOAD = ["uart"]
 
 MULTI_CONF = True
-CONF_DATA_BITS = "data_bits"
-CONF_STOP_BITS = "stop_bits"
-CONF_PARITY = "parity"
 CONF_CRYSTAL = "crystal"
 CONF_UART = "uart"
 CONF_TEST_MODE = "test_mode"
diff --git a/esphome/components/wifi/wifi_component.cpp b/esphome/components/wifi/wifi_component.cpp
index 1e6961b8bd..7d5d0133c1 100644
--- a/esphome/components/wifi/wifi_component.cpp
+++ b/esphome/components/wifi/wifi_component.cpp
@@ -2121,7 +2121,7 @@ bool WiFiComponent::can_proceed() {
 #endif
 
 void WiFiComponent::set_reboot_timeout(uint32_t reboot_timeout) { this->reboot_timeout_ = reboot_timeout; }
-bool WiFiComponent::is_connected() {
+bool WiFiComponent::is_connected() const {
   return this->state_ == WIFI_COMPONENT_STATE_STA_CONNECTED &&
          this->wifi_sta_connect_status_() == WiFiSTAConnectStatus::CONNECTED && !this->error_from_callback_;
 }
diff --git a/esphome/components/wifi/wifi_component.h b/esphome/components/wifi/wifi_component.h
index 63c7039f21..a6f03a08d9 100644
--- a/esphome/components/wifi/wifi_component.h
+++ b/esphome/components/wifi/wifi_component.h
@@ -443,7 +443,7 @@ class WiFiComponent : public Component {
 
   void set_reboot_timeout(uint32_t reboot_timeout);
 
-  bool is_connected();
+  bool is_connected() const;
 
   void set_power_save_mode(WiFiPowerSaveMode power_save);
   void set_min_auth_mode(WifiMinAuthMode min_auth_mode) { min_auth_mode_ = min_auth_mode; }
@@ -677,7 +677,7 @@ class WiFiComponent : public Component {
   bool wifi_apply_hostname_();
   bool wifi_sta_connect_(const WiFiAP &ap);
   void wifi_pre_setup_();
-  WiFiSTAConnectStatus wifi_sta_connect_status_();
+  WiFiSTAConnectStatus wifi_sta_connect_status_() const;
   bool wifi_scan_start_(bool passive);
 
 #ifdef USE_WIFI_AP
diff --git a/esphome/components/wifi/wifi_component_esp8266.cpp b/esphome/components/wifi/wifi_component_esp8266.cpp
index 8911bf15e0..bd6a18a99b 100644
--- a/esphome/components/wifi/wifi_component_esp8266.cpp
+++ b/esphome/components/wifi/wifi_component_esp8266.cpp
@@ -622,7 +622,7 @@ void WiFiComponent::wifi_pre_setup_() {
   this->wifi_mode_(false, false);
 }
 
-WiFiSTAConnectStatus WiFiComponent::wifi_sta_connect_status_() {
+WiFiSTAConnectStatus WiFiComponent::wifi_sta_connect_status_() const {
   station_status_t status = wifi_station_get_connect_status();
   if (status == STATION_GOT_IP)
     return WiFiSTAConnectStatus::CONNECTED;
diff --git a/esphome/components/wifi/wifi_component_esp_idf.cpp b/esphome/components/wifi/wifi_component_esp_idf.cpp
index 57bbceb1b8..734d186205 100644
--- a/esphome/components/wifi/wifi_component_esp_idf.cpp
+++ b/esphome/components/wifi/wifi_component_esp_idf.cpp
@@ -921,7 +921,7 @@ void WiFiComponent::wifi_process_event_(IDFWiFiEvent *data) {
   }
 }
 
-WiFiSTAConnectStatus WiFiComponent::wifi_sta_connect_status_() {
+WiFiSTAConnectStatus WiFiComponent::wifi_sta_connect_status_() const {
   if (s_sta_connected && this->got_ipv4_address_) {
 #if USE_NETWORK_IPV6 && (USE_NETWORK_MIN_IPV6_ADDR_COUNT > 0)
     if (this->num_ipv6_addresses_ >= USE_NETWORK_MIN_IPV6_ADDR_COUNT) {
diff --git a/esphome/components/wifi/wifi_component_libretiny.cpp b/esphome/components/wifi/wifi_component_libretiny.cpp
index 1c5490a3ac..4c4150e44d 100644
--- a/esphome/components/wifi/wifi_component_libretiny.cpp
+++ b/esphome/components/wifi/wifi_component_libretiny.cpp
@@ -634,7 +634,7 @@ void WiFiComponent::wifi_pre_setup_() {
   // Make sure WiFi is in clean state before anything starts
   this->wifi_mode_(false, false);
 }
-WiFiSTAConnectStatus WiFiComponent::wifi_sta_connect_status_() {
+WiFiSTAConnectStatus WiFiComponent::wifi_sta_connect_status_() const {
   // Use state machine instead of querying WiFi.status() directly
   // State is updated in main loop from queued events, ensuring thread safety
   switch (s_sta_state) {
diff --git a/esphome/components/wifi/wifi_component_pico_w.cpp b/esphome/components/wifi/wifi_component_pico_w.cpp
index 9b2c077dc5..270425d8c2 100644
--- a/esphome/components/wifi/wifi_component_pico_w.cpp
+++ b/esphome/components/wifi/wifi_component_pico_w.cpp
@@ -120,7 +120,7 @@ const char *get_disconnect_reason_str(uint8_t reason) {
   return "UNKNOWN";
 }
 
-WiFiSTAConnectStatus WiFiComponent::wifi_sta_connect_status_() {
+WiFiSTAConnectStatus WiFiComponent::wifi_sta_connect_status_() const {
   // Use cyw43_wifi_link_status instead of cyw43_tcpip_link_status because the Arduino
   // framework's __wrap_cyw43_cb_tcpip_init is a no-op — the SDK's internal netif
   // (cyw43_state.netif[]) is never initialized. cyw43_tcpip_link_status checks that netif's
diff --git a/esphome/components/zwave_proxy/__init__.py b/esphome/components/zwave_proxy/__init__.py
index 5be05bb464..d88f9f7041 100644
--- a/esphome/components/zwave_proxy/__init__.py
+++ b/esphome/components/zwave_proxy/__init__.py
@@ -41,6 +41,3 @@ async def to_code(config):
     await cg.register_component(var, config)
     await uart.register_uart_device(var, config)
     cg.add_define("USE_ZWAVE_PROXY")
-
-    # Request UART to wake the main loop when data arrives for low-latency processing
-    uart.request_wake_loop_on_rx()
diff --git a/esphome/const.py b/esphome/const.py
index 1611aeb101..7262a106d8 100644
--- a/esphome/const.py
+++ b/esphome/const.py
@@ -280,6 +280,7 @@ CONF_CUSTOM_PRESETS = "custom_presets"
 CONF_CYCLE = "cycle"
 CONF_DALLAS_ID = "dallas_id"
 CONF_DATA = "data"
+CONF_DATA_BITS = "data_bits"
 CONF_DATA_PIN = "data_pin"
 CONF_DATA_PINS = "data_pins"
 CONF_DATA_RATE = "data_rate"
@@ -759,6 +760,7 @@ CONF_PAGE_ID = "page_id"
 CONF_PAGES = "pages"
 CONF_PANASONIC = "panasonic"
 CONF_PARAMETERS = "parameters"
+CONF_PARITY = "parity"
 CONF_PASSWORD = "password"
 CONF_PATH = "path"
 CONF_PATTERN = "pattern"
@@ -961,6 +963,7 @@ CONF_STEP_PIN = "step_pin"
 CONF_STILL_THRESHOLD = "still_threshold"
 CONF_STOP = "stop"
 CONF_STOP_ACTION = "stop_action"
+CONF_STOP_BITS = "stop_bits"
 CONF_STORE_BASELINE = "store_baseline"
 CONF_SUBNET = "subnet"
 CONF_SUBSCRIBE_QOS = "subscribe_qos"
diff --git a/esphome/core/application.cpp b/esphome/core/application.cpp
index b1ece86701..c977fd66b3 100644
--- a/esphome/core/application.cpp
+++ b/esphome/core/application.cpp
@@ -79,24 +79,7 @@ static void insertion_sort_by_priority(Iterator first, Iterator last) {
   }
 }
 
-void Application::register_component_(Component *comp) {
-  if (comp == nullptr) {
-    ESP_LOGW(TAG, "Tried to register null component!");
-    return;
-  }
-
-  for (auto *c : this->components_) {
-    if (comp == c) {
-      ESP_LOGW(TAG, "Component %s already registered! (%p)", LOG_STR_ARG(c->get_component_log_str()), c);
-      return;
-    }
-  }
-  if (this->components_.size() >= ESPHOME_COMPONENT_COUNT) {
-    ESP_LOGE(TAG, "Cannot register component %s - at capacity!", LOG_STR_ARG(comp->get_component_log_str()));
-    return;
-  }
-  this->components_.push_back(comp);
-}
+void Application::register_component_(Component *comp) { this->components_.push_back(comp); }
 void Application::setup() {
   ESP_LOGI(TAG, "Running through setup()");
   ESP_LOGV(TAG, "Sorting components by setup priority");
@@ -525,8 +508,7 @@ void Application::enable_pending_loops_() {
     // Clear the pending flag and enable the loop
     component->pending_enable_loop_ = false;
     ESP_LOGVV(TAG, "%s loop enabled from ISR", LOG_STR_ARG(component->get_component_log_str()));
-    component->component_state_ &= ~COMPONENT_STATE_MASK;
-    component->component_state_ |= COMPONENT_STATE_LOOP;
+    component->set_component_state_(COMPONENT_STATE_LOOP);
 
     // Move to active section
     this->activate_looping_component_(i);
diff --git a/esphome/core/application.h b/esphome/core/application.h
index 0cc29af8e7..13e0f63885 100644
--- a/esphome/core/application.h
+++ b/esphome/core/application.h
@@ -108,6 +108,10 @@ namespace esphome::socket {
 class Socket;
 }  // namespace esphome::socket
 
+// Forward declarations for friend access from codegen-generated setup()
+void setup();           // NOLINT(readability-redundant-declaration) - may be declared in Arduino.h
+void original_setup();  // NOLINT(readability-redundant-declaration) - used by cpp unit tests
+
 namespace esphome {
 
 // Teardown timeout constant (in milliseconds)
@@ -247,13 +251,6 @@ class Application {
 
   /// Reserve space for components to avoid memory fragmentation
 
-  /// Register the component in this Application instance.
-  template<class C> C *register_component(C *c) {
-    static_assert(std::is_base_of<Component, C>::value, "Only Component subclasses can be registered");
-    this->register_component_((Component *) c);
-    return c;
-  }
-
   /// Set up all the registered components. Call this at the end of your setup() function.
   void setup();
 
@@ -503,11 +500,23 @@ class Application {
   /// On other platforms: uses UDP loopback socket
   void wake_loop_threadsafe();
 #endif
+
+#if defined(USE_WAKE_LOOP_THREADSAFE) && defined(USE_LWIP_FAST_SELECT)
+  /// Wake the main event loop from an ISR.
+  /// Uses vTaskNotifyGiveFromISR() — <1 us, ISR-safe.
+  /// Only available on platforms with fast select (ESP32, LibreTiny).
+  /// @param px_higher_priority_task_woken Set to pdTRUE if a context switch is needed.
+  static void IRAM_ATTR wake_loop_isrsafe(int *px_higher_priority_task_woken) {
+    esphome_lwip_wake_main_loop_from_isr(px_higher_priority_task_woken);
+  }
+#endif
 #endif
 
  protected:
   friend Component;
   friend class socket::Socket;
+  friend void ::setup();
+  friend void ::original_setup();
 
 #ifdef USE_SOCKET_SELECT_SUPPORT
   /// Fast path for Socket::ready() via friendship - skips negative fd check.
diff --git a/esphome/core/component.cpp b/esphome/core/component.cpp
index e14fae5e08..fd4e0d2984 100644
--- a/esphome/core/component.cpp
+++ b/esphome/core/component.cpp
@@ -297,10 +297,6 @@ void Component::mark_failed() {
   // Also remove from loop since failed components shouldn't loop
   App.disable_component_loop_(this);
 }
-void Component::set_component_state_(uint8_t state) {
-  this->component_state_ &= ~COMPONENT_STATE_MASK;
-  this->component_state_ |= state;
-}
 void Component::disable_loop() {
   if ((this->component_state_ & COMPONENT_STATE_MASK) != COMPONENT_STATE_LOOP_DONE) {
     ESP_LOGVV(TAG, "%s loop disabled", LOG_STR_ARG(this->get_component_log_str()));
@@ -387,31 +383,30 @@ bool Component::is_idle() const { return (this->component_state_ & COMPONENT_STA
 bool Component::can_proceed() { return true; }
 bool Component::status_has_warning() const { return this->component_state_ & STATUS_LED_WARNING; }
 bool Component::status_has_error() const { return this->component_state_ & STATUS_LED_ERROR; }
+bool Component::set_status_flag_(uint8_t flag) {
+  if ((this->component_state_ & flag) != 0)
+    return false;
+  this->component_state_ |= flag;
+  App.app_state_ |= flag;
+  return true;
+}
 
 void Component::status_set_warning(const char *message) {
-  // Don't spam the log. This risks missing different warning messages though.
-  if ((this->component_state_ & STATUS_LED_WARNING) != 0)
+  if (!this->set_status_flag_(STATUS_LED_WARNING))
     return;
-  this->component_state_ |= STATUS_LED_WARNING;
-  App.app_state_ |= STATUS_LED_WARNING;
   ESP_LOGW(TAG, "%s set Warning flag: %s", LOG_STR_ARG(this->get_component_log_str()),
            message ? message : LOG_STR_LITERAL("unspecified"));
 }
 void Component::status_set_warning(const LogString *message) {
-  // Don't spam the log. This risks missing different warning messages though.
-  if ((this->component_state_ & STATUS_LED_WARNING) != 0)
+  if (!this->set_status_flag_(STATUS_LED_WARNING))
     return;
-  this->component_state_ |= STATUS_LED_WARNING;
-  App.app_state_ |= STATUS_LED_WARNING;
   ESP_LOGW(TAG, "%s set Warning flag: %s", LOG_STR_ARG(this->get_component_log_str()),
            message ? LOG_STR_ARG(message) : LOG_STR_LITERAL("unspecified"));
 }
 void Component::status_set_error() { this->status_set_error((const LogString *) nullptr); }
 void Component::status_set_error(const char *message) {
-  if ((this->component_state_ & STATUS_LED_ERROR) != 0)
+  if (!this->set_status_flag_(STATUS_LED_ERROR))
     return;
-  this->component_state_ |= STATUS_LED_ERROR;
-  App.app_state_ |= STATUS_LED_ERROR;
   ESP_LOGE(TAG, "%s set Error flag: %s", LOG_STR_ARG(this->get_component_log_str()),
            message ? message : LOG_STR_LITERAL("unspecified"));
   if (message != nullptr) {
@@ -419,10 +414,8 @@ void Component::status_set_error(const char *message) {
   }
 }
 void Component::status_set_error(const LogString *message) {
-  if ((this->component_state_ & STATUS_LED_ERROR) != 0)
+  if (!this->set_status_flag_(STATUS_LED_ERROR))
     return;
-  this->component_state_ |= STATUS_LED_ERROR;
-  App.app_state_ |= STATUS_LED_ERROR;
   ESP_LOGE(TAG, "%s set Error flag: %s", LOG_STR_ARG(this->get_component_log_str()),
            message ? LOG_STR_ARG(message) : LOG_STR_LITERAL("unspecified"));
   if (message != nullptr) {
diff --git a/esphome/core/component.h b/esphome/core/component.h
index 2620e8eb2a..6b920da290 100644
--- a/esphome/core/component.h
+++ b/esphome/core/component.h
@@ -294,7 +294,16 @@ class Component {
   void call_dump_config_();
 
   /// Helper to set component state (clears state bits and sets new state)
-  void set_component_state_(uint8_t state);
+  inline void set_component_state_(uint8_t state) {
+    this->component_state_ &= ~COMPONENT_STATE_MASK;
+    this->component_state_ |= state;
+  }
+
+  /// Helper to set a status LED flag on both this component and the app.
+  /// Returns true if the flag was newly set, false if it was already set.
+  /// Note: Callers often use the return value to decide whether to log a warning/error,
+  /// so once a flag is set, subsequent (potentially different) messages may be suppressed.
+  bool set_status_flag_(uint8_t flag);
 
   /** Set an interval function with a unique name. Empty name means no cancelling possible.
    *
diff --git a/esphome/core/defines.h b/esphome/core/defines.h
index 5c982c94b1..181425c162 100644
--- a/esphome/core/defines.h
+++ b/esphome/core/defines.h
@@ -55,6 +55,7 @@
 #define USE_HOMEASSISTANT_TIME
 #define USE_HTTP_REQUEST_OTA_WATCHDOG_TIMEOUT 8000  // NOLINT
 #define USE_IMAGE
+#define USE_IMPROV_SERIAL
 #define USE_IMPROV_SERIAL_NEXT_URL
 #define USE_INFRARED
 #define USE_IR_RF
diff --git a/esphome/core/helpers.h b/esphome/core/helpers.h
index b606e68df3..65d590a5e6 100644
--- a/esphome/core/helpers.h
+++ b/esphome/core/helpers.h
@@ -133,6 +133,78 @@ template<typename T> class ConstVector {
   size_t size_;
 };
 
+/// Small buffer optimization - stores data inline when small, heap-allocates for large data
+/// This avoids heap fragmentation for common small allocations while supporting arbitrary sizes.
+/// Memory management is encapsulated - callers just use set() and data().
+template<size_t InlineSize = 8> class SmallInlineBuffer {
+ public:
+  SmallInlineBuffer() = default;
+  ~SmallInlineBuffer() {
+    if (!this->is_inline_())
+      delete[] this->heap_;
+  }
+
+  // Move constructor
+  SmallInlineBuffer(SmallInlineBuffer &&other) noexcept : len_(other.len_) {
+    if (other.is_inline_()) {
+      memcpy(this->inline_, other.inline_, this->len_);
+    } else {
+      this->heap_ = other.heap_;
+      other.heap_ = nullptr;
+    }
+    other.len_ = 0;
+  }
+
+  // Move assignment
+  SmallInlineBuffer &operator=(SmallInlineBuffer &&other) noexcept {
+    if (this != &other) {
+      if (!this->is_inline_())
+        delete[] this->heap_;
+      this->len_ = other.len_;
+      if (other.is_inline_()) {
+        memcpy(this->inline_, other.inline_, this->len_);
+      } else {
+        this->heap_ = other.heap_;
+        other.heap_ = nullptr;
+      }
+      other.len_ = 0;
+    }
+    return *this;
+  }
+
+  // Disable copy (would need deep copy of heap data)
+  SmallInlineBuffer(const SmallInlineBuffer &) = delete;
+  SmallInlineBuffer &operator=(const SmallInlineBuffer &) = delete;
+
+  /// Set buffer contents, allocating heap if needed
+  void set(const uint8_t *src, size_t size) {
+    // Free existing heap allocation if switching from heap to inline or different heap size
+    if (!this->is_inline_() && (size <= InlineSize || size != this->len_)) {
+      delete[] this->heap_;
+      this->heap_ = nullptr;  // Defensive: prevent use-after-free if logic changes
+    }
+    // Allocate new heap buffer if needed
+    if (size > InlineSize && (this->is_inline_() || size != this->len_)) {
+      this->heap_ = new uint8_t[size];  // NOLINT(cppcoreguidelines-owning-memory)
+    }
+    this->len_ = size;
+    memcpy(this->data(), src, size);
+  }
+
+  uint8_t *data() { return this->is_inline_() ? this->inline_ : this->heap_; }
+  const uint8_t *data() const { return this->is_inline_() ? this->inline_ : this->heap_; }
+  size_t size() const { return this->len_; }
+
+ protected:
+  bool is_inline_() const { return this->len_ <= InlineSize; }
+
+  size_t len_{0};
+  union {
+    uint8_t inline_[InlineSize]{};  // Zero-init ensures clean initial state
+    uint8_t *heap_;
+  };
+};
+
 /// Minimal static vector - saves memory by avoiding std::vector overhead
 template<typename T, size_t N> class StaticVector {
  public:
diff --git a/esphome/core/lwip_fast_select.c b/esphome/core/lwip_fast_select.c
index 88cf23b67e..da0f1f337a 100644
--- a/esphome/core/lwip_fast_select.c
+++ b/esphome/core/lwip_fast_select.c
@@ -126,6 +126,12 @@
 
 #include <stddef.h>
 
+// IRAM_ATTR is defined by esp_attr.h (included via FreeRTOS headers) on ESP32.
+// On LibreTiny it's not defined — provide a no-op fallback.
+#ifndef IRAM_ATTR
+#define IRAM_ATTR
+#endif
+
 // Compile-time verification of thread safety assumptions.
 // On ESP32 (Xtensa/RISC-V) and LibreTiny (ARM Cortex-M), naturally-aligned
 // reads/writes up to 32 bits are atomic.
@@ -225,4 +231,12 @@ void esphome_lwip_wake_main_loop(void) {
   }
 }
 
+// Wake the main loop from an ISR. ISR-safe variant.
+void IRAM_ATTR esphome_lwip_wake_main_loop_from_isr(int *px_higher_priority_task_woken) {
+  TaskHandle_t task = s_main_loop_task;
+  if (task != NULL) {
+    vTaskNotifyGiveFromISR(task, (BaseType_t *) px_higher_priority_task_woken);
+  }
+}
+
 #endif  // defined(USE_ESP32) || defined(USE_LIBRETINY)
diff --git a/esphome/core/lwip_fast_select.h b/esphome/core/lwip_fast_select.h
index b08c946212..b7a70a8f9f 100644
--- a/esphome/core/lwip_fast_select.h
+++ b/esphome/core/lwip_fast_select.h
@@ -28,6 +28,11 @@ void esphome_lwip_hook_socket(int fd);
 /// NOT ISR-safe — must only be called from task context.
 void esphome_lwip_wake_main_loop(void);
 
+/// Wake the main loop task from an ISR — costs <1 us.
+/// ISR-safe variant using vTaskNotifyGiveFromISR().
+/// @param px_higher_priority_task_woken Set to pdTRUE if a context switch is needed.
+void esphome_lwip_wake_main_loop_from_isr(int *px_higher_priority_task_woken);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/esphome/core/string_ref.h b/esphome/core/string_ref.h
index d502c4d27f..6047202753 100644
--- a/esphome/core/string_ref.h
+++ b/esphome/core/string_ref.h
@@ -81,6 +81,20 @@ class StringRef {
 
   operator std::string() const { return str(); }
 
+  /// Compare (compatible with std::string::compare)
+  int compare(const StringRef &other) const {
+    int result = std::memcmp(base_, other.base_, std::min(len_, other.len_));
+    if (result != 0)
+      return result;
+    if (len_ < other.len_)
+      return -1;
+    if (len_ > other.len_)
+      return 1;
+    return 0;
+  }
+  int compare(const char *s) const { return compare(StringRef(s)); }
+  int compare(const std::string &s) const { return compare(StringRef(s)); }
+
   /// Find first occurrence of substring, returns std::string::npos if not found.
   /// Note: Requires the underlying string to be null-terminated.
   size_type find(const char *s, size_type pos = 0) const {
diff --git a/esphome/cpp_helpers.py b/esphome/cpp_helpers.py
index 954a28d3d1..b673eaa7e1 100644
--- a/esphome/cpp_helpers.py
+++ b/esphome/cpp_helpers.py
@@ -79,7 +79,7 @@ async def register_component(var, config):
     if name is not None:
         add(var.set_component_source(LogStringLiteral(name)))
 
-    add(App.register_component(var))
+    add(App.register_component_(var))
     return var
 
 
diff --git a/esphome/util.py b/esphome/util.py
index 7b896de27e..686aa74306 100644
--- a/esphome/util.py
+++ b/esphome/util.py
@@ -24,11 +24,14 @@ class RegistryEntry:
         fun: Callable[..., Any],
         type_id: "MockObjClass",
         schema: "Schema",
+        *,
+        synchronous: bool = False,
     ):
         self.name = name
         self.fun = fun
         self.type_id = type_id
         self.raw_schema = schema
+        self.synchronous = synchronous
 
     @property
     def coroutine_fun(self):
@@ -49,9 +52,18 @@ class Registry(dict[str, RegistryEntry]):
         self.base_schema = base_schema or {}
         self.type_id_key = type_id_key
 
-    def register(self, name: str, type_id: "MockObjClass", schema: "Schema"):
+    def register(
+        self,
+        name: str,
+        type_id: "MockObjClass",
+        schema: "Schema",
+        *,
+        synchronous: bool = False,
+    ):
         def decorator(fun: Callable[..., Any]):
-            self[name] = RegistryEntry(name, fun, type_id, schema)
+            self[name] = RegistryEntry(
+                name, fun, type_id, schema, synchronous=synchronous
+            )
             return fun
 
         return decorator
diff --git a/script/ci-custom.py b/script/ci-custom.py
index 85a446ba0d..f428eb0821 100755
--- a/script/ci-custom.py
+++ b/script/ci-custom.py
@@ -959,7 +959,7 @@ def main():
             continue
         run_checks(LINT_CONTENT_CHECKS, fname, fname, content)
 
-    run_checks(LINT_POST_CHECKS, "POST")
+    run_checks(LINT_POST_CHECKS, Path("POST"))
 
     for f, errs in sorted(errors.items()):
         bold = functools.partial(styled, colorama.Style.BRIGHT)
diff --git a/tests/component_tests/deep_sleep/test_deep_sleep.py b/tests/component_tests/deep_sleep/test_deep_sleep.py
index 11f1bcb58e..41ddd72feb 100644
--- a/tests/component_tests/deep_sleep/test_deep_sleep.py
+++ b/tests/component_tests/deep_sleep/test_deep_sleep.py
@@ -8,7 +8,7 @@ def test_deep_sleep_setup(generate_main):
     main_cpp = generate_main("tests/component_tests/deep_sleep/test_deep_sleep1.yaml")
 
     assert "deepsleep = new deep_sleep::DeepSleepComponent();" in main_cpp
-    assert "App.register_component(deepsleep);" in main_cpp
+    assert "App.register_component_(deepsleep);" in main_cpp
 
 
 def test_deep_sleep_sleep_duration(generate_main):
diff --git a/tests/component_tests/ota/test_web_server_ota.py b/tests/component_tests/ota/test_web_server_ota.py
index 794eaac9be..4b3a4c705c 100644
--- a/tests/component_tests/ota/test_web_server_ota.py
+++ b/tests/component_tests/ota/test_web_server_ota.py
@@ -27,7 +27,7 @@ def test_web_server_ota_generated(generate_main: Callable[[str], str]) -> None:
     assert "global_web_server_base" in main_cpp
 
     # Check component is registered
-    assert "App.register_component(web_server_webserverotacomponent_id)" in main_cpp
+    assert "App.register_component_(web_server_webserverotacomponent_id)" in main_cpp
 
 
 def test_web_server_ota_with_callbacks(generate_main: Callable[[str], str]) -> None:
diff --git a/tests/components/esp32/test.esp32-idf.yaml b/tests/components/esp32/test.esp32-idf.yaml
index f80c854de5..da85aa3b0f 100644
--- a/tests/components/esp32/test.esp32-idf.yaml
+++ b/tests/components/esp32/test.esp32-idf.yaml
@@ -10,6 +10,7 @@ esp32:
       use_full_certificate_bundle: false  # Test CMN bundle (default)
       include_builtin_idf_components:
         - freertos  # Test escape hatch (freertos is always included anyway)
+      enable_full_printf: false
       disable_debug_stubs: true
       disable_ocd_aware: true
       disable_usb_serial_jtag_secondary: true
diff --git a/tests/components/sen6x/common.yaml b/tests/components/sen6x/common.yaml
index fdb8a485e2..61ff9f1e0c 100644
--- a/tests/components/sen6x/common.yaml
+++ b/tests/components/sen6x/common.yaml
@@ -12,19 +12,19 @@ sensor:
       accuracy_decimals: 0
     pm_1_0:
       name: PM <1µm Weight concentration
-      id: pm_1_0
+      id: sen6x_pm_1_0
       accuracy_decimals: 1
     pm_2_5:
       name: PM <2.5µm Weight concentration
-      id: pm_2_5
+      id: sen6x_pm_2_5
       accuracy_decimals: 1
     pm_4_0:
       name: PM <4µm Weight concentration
-      id: pm_4_0
+      id: sen6x_pm_4_0
       accuracy_decimals: 1
     pm_10_0:
       name: PM <10µm Weight concentration
-      id: pm_10_0
+      id: sen6x_pm_10_0
       accuracy_decimals: 1
     nox:
       name: NOx
diff --git a/tests/dummy_main.cpp b/tests/dummy_main.cpp
index 52f1fbd319..3ccf35e04d 100644
--- a/tests/dummy_main.cpp
+++ b/tests/dummy_main.cpp
@@ -16,10 +16,10 @@ void setup() {
   auto *log = new logger::Logger(115200);  // NOLINT
   log->pre_setup();
   log->set_uart_selection(logger::UART_SELECTION_UART0);
-  App.register_component(log);
+  App.register_component_(log);
 
   auto *wifi = new wifi::WiFiComponent();  // NOLINT
-  App.register_component(wifi);
+  App.register_component_(wifi);
   wifi::WiFiAP ap;
   ap.set_ssid("Test SSID");
   ap.set_password("password1");
diff --git a/tests/unit_tests/test_automation.py b/tests/unit_tests/test_automation.py
new file mode 100644
index 0000000000..61fef8201d
--- /dev/null
+++ b/tests/unit_tests/test_automation.py
@@ -0,0 +1,177 @@
+"""Tests for esphome.automation module."""
+
+from collections.abc import Generator
+from unittest.mock import patch
+
+import pytest
+
+from esphome.automation import has_non_synchronous_actions
+from esphome.util import RegistryEntry
+
+
+def _make_registry(non_synchronous_actions: set[str]) -> dict[str, RegistryEntry]:
+    """Create a mock ACTION_REGISTRY with specified non-synchronous actions.
+
+    Uses the default synchronous=False, matching the real registry behavior.
+    """
+    registry: dict[str, RegistryEntry] = {}
+    for name in non_synchronous_actions:
+        registry[name] = RegistryEntry(name, lambda: None, None, None)
+    return registry
+
+
+@pytest.fixture
+def mock_registry() -> Generator[dict[str, RegistryEntry]]:
+    """Fixture that patches ACTION_REGISTRY with delay, wait_until, script.wait as non-synchronous."""
+    registry: dict[str, RegistryEntry] = _make_registry(
+        {"delay", "wait_until", "script.wait"}
+    )
+    registry["logger.log"] = RegistryEntry(
+        "logger.log", lambda: None, None, None, synchronous=True
+    )
+    with patch("esphome.automation.ACTION_REGISTRY", registry):
+        yield registry
+
+
+def test_has_non_synchronous_actions_empty_list(
+    mock_registry: dict[str, RegistryEntry],
+) -> None:
+    assert has_non_synchronous_actions([]) is False
+
+
+def test_has_non_synchronous_actions_empty_dict(
+    mock_registry: dict[str, RegistryEntry],
+) -> None:
+    assert has_non_synchronous_actions({}) is False
+
+
+def test_has_non_synchronous_actions_non_dict_non_list(
+    mock_registry: dict[str, RegistryEntry],
+) -> None:
+    assert has_non_synchronous_actions("string") is False
+    assert has_non_synchronous_actions(42) is False
+    assert has_non_synchronous_actions(None) is False
+
+
+def test_has_non_synchronous_actions_delay(
+    mock_registry: dict[str, RegistryEntry],
+) -> None:
+    assert has_non_synchronous_actions([{"delay": "1s"}]) is True
+
+
+def test_has_non_synchronous_actions_wait_until(
+    mock_registry: dict[str, RegistryEntry],
+) -> None:
+    assert has_non_synchronous_actions([{"wait_until": {"condition": {}}}]) is True
+
+
+def test_has_non_synchronous_actions_script_wait(
+    mock_registry: dict[str, RegistryEntry],
+) -> None:
+    assert has_non_synchronous_actions([{"script.wait": "script_id"}]) is True
+
+
+def test_has_non_synchronous_actions_synchronous(
+    mock_registry: dict[str, RegistryEntry],
+) -> None:
+    assert has_non_synchronous_actions([{"logger.log": "hello"}]) is False
+
+
+def test_has_non_synchronous_actions_unknown_not_in_registry(
+    mock_registry: dict[str, RegistryEntry],
+) -> None:
+    """Unknown actions not in registry are not flagged (only registered actions count)."""
+    assert has_non_synchronous_actions([{"unknown.action": "value"}]) is False
+
+
+def test_has_non_synchronous_actions_default_non_synchronous(
+    mock_registry: dict[str, RegistryEntry],
+) -> None:
+    """Actions registered without explicit synchronous=True default to non-synchronous."""
+    mock_registry["some.action"] = RegistryEntry(
+        "some.action", lambda: None, None, None
+    )
+    assert has_non_synchronous_actions([{"some.action": "value"}]) is True
+
+
+def test_has_non_synchronous_actions_nested_in_then(
+    mock_registry: dict[str, RegistryEntry],
+) -> None:
+    """Non-synchronous action nested inside a synchronous action's then block."""
+    actions: list[dict[str, object]] = [
+        {
+            "logger.log": "first",
+            "then": [{"delay": "1s"}],
+        }
+    ]
+    assert has_non_synchronous_actions(actions) is True
+
+
+def test_has_non_synchronous_actions_deeply_nested(
+    mock_registry: dict[str, RegistryEntry],
+) -> None:
+    """Non-synchronous action deeply nested in action structure."""
+    actions: list[dict[str, object]] = [
+        {
+            "if": {
+                "then": [
+                    {"logger.log": "hello"},
+                    {"delay": "500ms"},
+                ]
+            }
+        }
+    ]
+    assert has_non_synchronous_actions(actions) is True
+
+
+def test_has_non_synchronous_actions_none_in_nested(
+    mock_registry: dict[str, RegistryEntry],
+) -> None:
+    """No non-synchronous actions even with nesting."""
+    actions: list[dict[str, object]] = [
+        {
+            "if": {
+                "then": [
+                    {"logger.log": "hello"},
+                ]
+            }
+        }
+    ]
+    assert has_non_synchronous_actions(actions) is False
+
+
+def test_has_non_synchronous_actions_multiple_one_non_synchronous(
+    mock_registry: dict[str, RegistryEntry],
+) -> None:
+    assert (
+        has_non_synchronous_actions(
+            [
+                {"logger.log": "first"},
+                {"delay": "1s"},
+                {"logger.log": "second"},
+            ]
+        )
+        is True
+    )
+
+
+def test_has_non_synchronous_actions_multiple_all_synchronous(
+    mock_registry: dict[str, RegistryEntry],
+) -> None:
+    assert (
+        has_non_synchronous_actions(
+            [
+                {"logger.log": "first"},
+                {"logger.log": "second"},
+            ]
+        )
+        is False
+    )
+
+
+def test_has_non_synchronous_actions_dict_input(
+    mock_registry: dict[str, RegistryEntry],
+) -> None:
+    """Direct dict input (single action)."""
+    assert has_non_synchronous_actions({"delay": "1s"}) is True
+    assert has_non_synchronous_actions({"logger.log": "hello"}) is False
diff --git a/tests/unit_tests/test_cpp_helpers.py b/tests/unit_tests/test_cpp_helpers.py
index 2618803fec..82ded409c7 100644
--- a/tests/unit_tests/test_cpp_helpers.py
+++ b/tests/unit_tests/test_cpp_helpers.py
@@ -16,7 +16,7 @@ async def test_gpio_pin_expression__conf_is_none(monkeypatch):
 async def test_register_component(monkeypatch):
     var = Mock(base="foo.bar")
 
-    app_mock = Mock(register_component=Mock(return_value=var))
+    app_mock = Mock(register_component_=Mock(return_value=var))
     monkeypatch.setattr(ch, "App", app_mock)
 
     core_mock = Mock(component_ids=["foo.bar"])
@@ -29,7 +29,7 @@ async def test_register_component(monkeypatch):
 
     assert actual is var
     assert add_mock.call_count == 2
-    app_mock.register_component.assert_called_with(var)
+    app_mock.register_component_.assert_called_with(var)
     assert core_mock.component_ids == []
 
 
@@ -48,7 +48,7 @@ async def test_register_component__no_component_id(monkeypatch):
 async def test_register_component__with_setup_priority(monkeypatch):
     var = Mock(base="foo.bar")
 
-    app_mock = Mock(register_component=Mock(return_value=var))
+    app_mock = Mock(register_component_=Mock(return_value=var))
     monkeypatch.setattr(ch, "App", app_mock)
 
     core_mock = Mock(component_ids=["foo.bar"])
@@ -68,5 +68,5 @@ async def test_register_component__with_setup_priority(monkeypatch):
     assert actual is var
     add_mock.assert_called()
     assert add_mock.call_count == 4
-    app_mock.register_component.assert_called_with(var)
+    app_mock.register_component_.assert_called_with(var)
     assert core_mock.component_ids == []