feat(l2): Gallery app (screenshots as thumbnails, full view with swipe and delete, the saved trails), the clock from NTP while WiFi is up (the router's server from DHCP first), tabs switch on release, Home apps out of Settings

- Gallery: thumbnails 30 to a page, built only while the screen is still (a decode held the loop and a scroll read as a tap)
- segmented(): CLICK_TRIG, so a swipe starting on a screen's tabs doesn't switch them
- Settings > Device > Home apps removed (hold an app on Home instead)
- platformio.ini: a note that the L2 has no microphone on GPIO15 (verified on hardware)

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

variants/wio-tracker-l2/platformio.ini

@@ -43,6 +43,9 @@ build_flags = ${esp32_base.build_flags}
   -D PIN_I2S_BCK=11
   -D PIN_I2S_WS=12
   -D PIN_I2S_DOUT=16
+  ; No microphone: Seeed's pin list has CODEC_I2S0_SDOUT on GPIO15, but on a
+  ; retail unit (2026-10) it read flat -1 with the codec's ADC on, and stayed
+  ; so with the codec's output muted -- the line isn't the codec's.
   -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