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>

examples/companion_radio/ui-lvgl/Theme.h

@@ -22,7 +22,7 @@ namespace theme {
   static const int ROW_H   = 44;    // list row (touch target)
 
   // Type -- Noto Sans, generated by fonts/generate.sh (declared in lv_conf.h).
-  // ui_font_40 holds digits / ':' / '-' only (clock).
+  // ui_font_40 holds digits / ':' / '-' / '.' only (clock, timer, stopwatch).
   #define THEME_FONT_SMALL  (&ui_font_12)
   #define THEME_FONT_BODY   (&ui_font_14)
   #define THEME_FONT_TITLE  (&ui_font_16)
@@ -33,4 +33,10 @@ namespace theme {
   #define UI_SYMBOL_STAR    "\xEF\x80\x85"   // U+F005, favourite
   #define UI_SYMBOL_MAP     "\xEF\x89\xB9"   // U+F279
   #define UI_SYMBOL_USERS   "\xEF\x83\x80"   // U+F0C0, Nearby
+  #define UI_SYMBOL_COMPASS "\xEF\x85\x8E"   // U+F14E, Navigate
+  #define UI_SYMBOL_FLAG    "\xEF\x80\xA4"   // U+F024, waypoint
+  #define UI_SYMBOL_PIN     "\xEF\x8F\x85"   // U+F3C5, mark here
+  #define UI_SYMBOL_CLOCK   "\xEF\x80\x97"   // U+F017, Clock tools
+  #define UI_SYMBOL_STOPWATCH "\xEF\x8B\xB2" // U+F2F2
+  #define UI_SYMBOL_RADIO   "\xEF\x94\x99"   // U+F519, broadcast tower
 }