Address review: empty-table failure semantics, async abort guard, StaticVector nodes

- A zero-service table on a client with nodes is treated as a failed
  discovery (warn, release, charge the backoff, disconnect): a real GATT
  peer always exposes at least GAP/GATT, so an empty table means the
  materialization failed and the connection must retry instead of
  sitting inert behind a successful on_connect
- The fan-out abort guard also tests cancel_requested_, covering the
  normal async teardown a node starts from on_connected (the state-only
  check caught just the synchronous refusal)
- nodes_ becomes a StaticVector sized by ESPHOME_BLE_CLIENT_MAX_NODES:
  the client requests a baseline slot, each neutral write action (which
  registers itself in its constructor) requests one, and the define
  rides defines.h for analysis - no realloc machinery on the rp2 target
- The Bluedroid empty-table return logs its quiet cases; the
  service_table=False stub notes the misconfiguration it implies

esphome/components/ble_client/__init__.py

@@ -350,6 +350,9 @@ async def ble_connect_to_code(config, action_id, template_arg, args):
 )
 async def ble_write_to_code(config, action_id, template_arg, args):
     parent = await cg.get_variable(config[CONF_ID])
+    if not CORE.is_esp32:
+        # The neutral action registers itself as a node in its constructor.
+        _request_node_slot()
     var = cg.new_Pvariable(action_id, template_arg, parent)
 
     value = config[CONF_VALUE]
@@ -448,7 +451,13 @@ async def _to_code_esp32(config: ConfigType) -> cg.MockObj:
     return var
 
 
+# Sizes the neutral client's node storage; the client itself requests a
+# baseline slot so the define exists on every build that compiles the engine.
+_request_node_slot = cg.slot_counter("ESPHOME_BLE_CLIENT_MAX_NODES")
+
+
 async def _to_code_gatt(config: ConfigType) -> cg.MockObj:
+    _request_node_slot()
     backend = await bluetooth_connection.new_gatt_backend(config)
     var = cg.new_Pvariable(config[CONF_ID])
     await cg.register_component(var, config)

esphome/components/ble_client/ble_client_gatt.cpp

@@ -160,13 +160,19 @@ void BLEClient::on_service_discovery_done(int error) {
     // would pay the build/free cycle on every (re)connect for nothing.
     auto table = this->backend_->get_service_table();
     if (table.service_count == 0) {
-      // A service-less device or a failed materialization: either way the
-      // nodes cannot resolve, so say so instead of sitting inert.
-      ESP_LOGW(TAG, "[%s] Service table is empty; nodes will not resolve", this->address_str_);
+      // A failed materialization is indistinguishable from a service-less
+      // peer, and a real GATT peer always exposes at least GAP/GATT: treat
+      // it as a discovery failure so the connection retries instead of
+      // sitting inert behind a successful-looking on_connect.
+      ESP_LOGW(TAG, "[%s] Service table is empty; treating as failed discovery", this->address_str_);
+      this->backend_->release_services();
+      this->register_failure_();
+      this->disconnect();
+      return;
     }
     for (auto *node : this->nodes_) {
       node->on_connected(table);
-      if (this->state_ != State::CONNECTED) {
+      if (this->state_ != State::CONNECTED || this->cancel_requested_) {
         // A node tore the link down mid-fan-out: on_disconnect fires with no
         // preceding on_connect, so leave a trace of why.
         ESP_LOGW(TAG, "[%s] A node aborted the connection during setup", this->address_str_);

esphome/components/ble_client/ble_client_gatt.h

@@ -23,7 +23,6 @@
 
 #include <cstdint>
 #include <functional>
-#include <vector>
 
 namespace esphome::ble_client {
 
@@ -133,7 +132,8 @@ class BLEClient : public Component,
 
   // Group 1: pointers / containers
   ble_device_base::BLEGattConnection *backend_{nullptr};
-  std::vector<BLEClientNode *> nodes_;  // filled during setup, never after
+  // Codegen-sized (ESPHOME_BLE_CLIENT_MAX_NODES); filled during setup.
+  StaticVector<BLEClientNode *, ESPHOME_BLE_CLIENT_MAX_NODES> nodes_;
 
   // Group 2: 8-byte types
   uint64_t address_{0};

esphome/components/bluetooth_connection/bluetooth_connection_bluedroid.cpp

@@ -324,6 +324,10 @@ void BluedroidGattClient::release_services() {
 ble_device_base::GattServiceTable BluedroidGattClient::get_service_table() {
   if (this->table_storage_ == nullptr &&
       (this->services_released_ || this->service_total_ == 0 || !this->build_service_table_())) {
+    // Released / no services / failed build all collapse to empty; the
+    // build failures warned above, log the quiet two.
+    ESP_LOGD(TAG, "[%d] No service table (released=%d, services=%u)", this->connection_index_, this->services_released_,
+             this->service_total_);
     return {};
   }
   return this->table_view_();

esphome/components/bluetooth_connection/bluetooth_connection_bluedroid.h

@@ -80,6 +80,8 @@ class BluedroidGattClient final : public esp32_ble_tracker::ESPBTClient, public
 #ifdef USE_BLE_GATT_SERVICE_TABLE
   ble_device_base::GattServiceTable get_service_table();
 #else
+  // A direct consumer reaching this stub misconfigured its codegen
+  // (service_table=False): the empty table reads as a service-less peer.
   ble_device_base::GattServiceTable get_service_table() { return {}; }
 #endif
   void release_services();

esphome/core/defines.h

@@ -474,6 +474,7 @@
 #define ESPHOME_BLE_DEVICE_BASE_LISTENER_COUNT 1
 #define USE_BLE_GATT_CLIENT
 #define ESPHOME_BLE_GATT_CLIENT_COUNT 1
+#define ESPHOME_BLE_CLIENT_MAX_NODES 1
 #define USE_RP2040_VARIANT_RP2040
 #define USE_SPI
 #ifndef USE_ETHERNET