feat(wio-tracker-l1): add settings screen and companion radio improvements

Settings screen (UI_HAS_JOYSTICK_UPDOWN build variant):
- Display brightness (5 levels, contrast curve tuned for SH1106 non-linearity)
- Buzzer on/off (respected at startup, no more forced unmute)
- TX power (2–22 dBm)
- Auto-off delay (5s / 15s / 30s / 60s / never)
- GPS update interval (off / 30s / 1min / 5min / 15min / 30min)
- Timezone offset (UTC-12..+14) for clock screen
- Low battery auto-shutdown threshold (off / 3.0–3.5V, default 3.4V)
- Battery display mode (icon / % / voltage)

Battery:
- EMA filter (alpha=0.2) on ADC readings to smooth voltage spikes from uneven load
- Battery % calculated using low_batt_mv as 0% anchor
- Mute icon repositions dynamically based on battery display width

Clock screen on HomeScreen showing time/date with timezone support.

Build:
- _settings variants added for USB and BLE companion radio builds
- Automatic UF2 generation on every build via create-uf2.py post-script
- UI_HAS_JOYSTICK_UPDOWN flag guards joystick_up/down to avoid breaking other boards

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

examples/companion_radio/MyMesh.cpp

@@ -868,6 +868,11 @@ MyMesh::MyMesh(mesh::Radio &radio, mesh::RNG &rng, mesh::RTCClock &rtc, SimpleMe
   _prefs.tx_power_dbm = LORA_TX_POWER;
   _prefs.gps_enabled = 0;       // GPS disabled by default
   _prefs.gps_interval = 0;      // No automatic GPS updates by default
+  _prefs.display_brightness = 2; // medium brightness by default
+  _prefs.auto_off_secs = 15;    // 15 seconds auto-off by default
+  _prefs.tz_offset_hours = 0;  // UTC by default
+  _prefs.low_batt_mv = 3400;  // auto-shutdown at 3.4V by default
+  _prefs.batt_display_mode = 0; // icon by default
   //_prefs.rx_delay_base = 10.0f;  enable once new algo fixed
 #if defined(USE_SX1262) || defined(USE_SX1268)
 #ifdef SX126X_RX_BOOSTED_GAIN