feat(ui-core,ui-lvgl): sound in the Core, L2 speaker via ES8311, Sound settings, melody editor

- genericBuzzer I2S path (BUZZER_I2S): an audio task synthesises the notes
  with eased edges and keeps the DMA queue fed with silence between sounds;
  ES8311 setup; amp powered through the board only around sounds
- ui-core/SoundControl.h (mode, volume, built-in sounds, melody model),
  SoundNotifier moved to the Core, chanctl::melody, schema Sound page
- L2: notifications, alarm / timer ring, locator sounds, Settings > Sound,
  melody editor with the playing note lit, per-chat sound, mute icon
- noteIndex() on every buzzer backend; scrolling popups past screen height

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

variants/wio-tracker-l2/platformio.ini

@@ -36,6 +36,14 @@ build_flags = ${esp32_base.build_flags}
   -D PIN_GPS_TX=18 ; L76K TX -> ESP32 RX
   -D PIN_GPS_RX=17 ; L76K RX <- ESP32 TX
   -D GPS_BAUD_RATE=9600
+  ; ES8311 codec (I2C 0x18) -> class-D amp (power on expander P12) -> speaker.
+  ; A frontend opts in with -D PIN_BUZZER=-1 -D BUZZER_I2S (genericBuzzer's
+  ; I2S path, src/helpers/ui/buzzer.cpp) and +<helpers/ui/buzzer.cpp>.
+  -D PIN_I2S_MCLK=10
+  -D PIN_I2S_BCK=11
+  -D PIN_I2S_WS=12
+  -D PIN_I2S_DOUT=16
+  -D BUZZER_CODEC_ES8311=0x18
   -D ENV_SKIP_GPS_DETECT=1 ; GPS is always present, powered via IO expander
   ; disable ALL env sensor I2C probes: this bus carries six onboard chips
   ; (TCA9535 0x21, AW35615 0x22, LP5814 0x2C, ADS1115 0x48, GT911 0x5D,

variants/wio-tracker-l2/target.cpp

@@ -18,6 +18,10 @@ EnvironmentSensorManager sensors(gps);
   MomentaryButton user_btn(PIN_USER_BTN, 1000, true, true);
 #endif
 
+#ifdef BUZZER_I2S
+void buzzerAmpPower(bool on) { board.setSpeakerAmp(on); }
+#endif
+
 bool radio_init() {
   MESH_DEBUG_PRINTLN("radio_init: rtc + sx1262 init");
   fallback_clock.begin();