[core] Mark leaf Component subclasses as final (#14833)

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

esphome/components/api/api_server.h

@@ -36,11 +36,11 @@ struct SavedNoisePsk {
 } PACKED;  // NOLINT
 #endif
 
-class APIServer : public Component,
-                  public Controller
+class APIServer final : public Component,
+                        public Controller
 #ifdef USE_CAMERA
     ,
-                  public camera::CameraListener
+                        public camera::CameraListener
 #endif
 {
  public:

esphome/components/binary_sensor/filter.h

@@ -37,7 +37,7 @@ class TimeoutFilter : public Filter, public Component {
   TemplatableValue<uint32_t> timeout_delay_{};
 };
 
-class DelayedOnOffFilter : public Filter, public Component {
+class DelayedOnOffFilter final : public Filter, public Component {
  public:
   optional<bool> new_value(bool value) override;
 

esphome/components/gpio/binary_sensor/gpio_binary_sensor.h

@@ -39,7 +39,7 @@ class GPIOBinarySensorStore {
   Component *component_{nullptr};  // Pointer to the component for enable_loop_soon_any_context()
 };
 
-class GPIOBinarySensor : public binary_sensor::BinarySensor, public Component {
+class GPIOBinarySensor final : public binary_sensor::BinarySensor, public Component {
  public:
   // No destructor needed: ESPHome components are created at boot and live forever.
   // Interrupts are only detached on reboot when memory is cleared anyway.

esphome/components/gpio/switch/gpio_switch.h

@@ -8,7 +8,7 @@
 namespace esphome {
 namespace gpio {
 
-class GPIOSwitch : public switch_::Switch, public Component {
+class GPIOSwitch final : public switch_::Switch, public Component {
  public:
   void set_pin(GPIOPin *pin) { pin_ = pin; }
 

esphome/components/homeassistant/time/homeassistant_time.h

@@ -7,7 +7,7 @@
 namespace esphome {
 namespace homeassistant {
 
-class HomeassistantTime : public time::RealTimeClock {
+class HomeassistantTime final : public time::RealTimeClock {
  public:
   void setup() override;
   void update() override;

esphome/components/md5/md5.h

@@ -32,7 +32,7 @@
 namespace esphome {
 namespace md5 {
 
-class MD5Digest : public HashBase {
+class MD5Digest final : public HashBase {
  public:
   MD5Digest() = default;
   ~MD5Digest() override;

esphome/components/preferences/syncer.h

@@ -6,7 +6,7 @@
 namespace esphome {
 namespace preferences {
 
-class IntervalSyncer : public Component {
+class IntervalSyncer final : public Component {
  public:
   void set_write_interval(uint32_t write_interval) { this->write_interval_ = write_interval; }
   void setup() override {

esphome/components/restart/button/restart_button.h

@@ -6,7 +6,7 @@
 namespace esphome {
 namespace restart {
 
-class RestartButton : public button::Button, public Component {
+class RestartButton final : public button::Button, public Component {
  public:
   void dump_config() override;
 

esphome/components/safe_mode/button/safe_mode_button.h

@@ -7,7 +7,7 @@
 namespace esphome {
 namespace safe_mode {
 
-class SafeModeButton : public button::Button, public Component {
+class SafeModeButton final : public button::Button, public Component {
  public:
   void dump_config() override;
   void set_safe_mode(SafeModeComponent *safe_mode_component);

esphome/components/sha256/sha256.h

@@ -48,7 +48,7 @@ namespace esphome::sha256 {
 ///   hasher.init();
 ///   hasher.add(data, len);
 ///   hasher.calculate();
-class SHA256 : public esphome::HashBase {
+class SHA256 final : public esphome::HashBase {
  public:
   SHA256() = default;
   ~SHA256() override;

esphome/components/version/version_text_sensor.h

@@ -5,7 +5,7 @@
 
 namespace esphome::version {
 
-class VersionTextSensor : public text_sensor::TextSensor, public Component {
+class VersionTextSensor final : public text_sensor::TextSensor, public Component {
  public:
   void set_hide_hash(bool hide_hash);
   void set_hide_timestamp(bool hide_timestamp);

esphome/components/wifi/wifi_component.h

@@ -399,7 +399,7 @@ class WiFiPowerSaveListener {
 };
 
 /// This component is responsible for managing the ESP WiFi interface.
-class WiFiComponent : public Component {
+class WiFiComponent final : public Component {
  public:
   /// Construct a WiFiComponent.
   WiFiComponent();