feat(ui-lvgl): navigation map, clock tools, settings pages, radio

- Home > Map is the navigation map: waypoints (list, add at GPS / by
  coordinates / long-press spot), live shares, trail recording + tools
  (save, load, GPX export, track back), live share controls, target bar
  with ETA; the nodes map opens from Nearby.
- Map: smooth panning (no decode during a drag, idle read-ahead, cached
  coarser stand-ins), overzoom limited to 2 levels, resumable downloads,
  map credit behind a "©" and in Settings > About; target ring and trail
  computed in double.
- Home in swipeable pages; Clock (alarm, timer, stopwatch, ring card).
- Settings rendered from the Core schema (display & power with a
  brightness slider, messages & contacts, trail / live share / alerts),
  GPS switch, Radio screen; low-battery shutdown.
- WioTrackerL2Display: honour the 0-4 brightness level.
- docs: L2 hardware checklist, ui-core notes.

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

variants/wio-tracker-l2/WioTrackerL2Display.h

@@ -162,6 +162,12 @@ class WioTrackerL2Display : public LGFXDisplay {
 public:
   WioTrackerL2Display() : LGFXDisplay(320, 240, disp) {}
 
+  // NodePrefs::display_brightness level 0-4 -> backlight PWM
+  void setBrightness(uint8_t level) override {
+    static const uint8_t PWM[5] = { 20, 60, 120, 190, 255 };
+    display->setBrightness(PWM[level > 4 ? 4 : level]);
+  }
+
   // direct access to the LGFX device (LVGL flush/touch glue)
   lgfx::LGFX_Device* lgfxDevice() { return &disp; }