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>

examples/companion_radio/ui-lvgl/HomeScreen.h

@@ -8,7 +8,7 @@
 //   map          -- a minimap round your position, framing anyone sharing
 //                   theirs and the target; tap for the Navigation map
 //   apps         -- the tools, 3x2 to a page, in the user's order with some
-//                   maybe hidden (Settings > Home apps, or hold an app)
+//                   maybe hidden (hold an app)
 //
 // Single-TU fragment: included by ui-lvgl/UITask.cpp after NavMap.h (the
 // minimap draws with the map's tile cache).
@@ -34,6 +34,7 @@ static const App APP_LIST[] = {
   { 'A', UI_SYMBOL_KEY,      "Admin",       onOpenAdminPick, false },
   { 'D', UI_SYMBOL_CHART,    "Diagnostics", onOpenDiag,      false },
   { 'L', UI_SYMBOL_BULB,     "Flashlight",  onOpenFlashlight, false },
+  { 'P', LV_SYMBOL_IMAGE,    "Gallery",     onOpenGallery,   false },
 };
 static const int APP_COUNT = sizeof(APP_LIST) / sizeof(APP_LIST[0]);
 static const int PER_PAGE = 6;
@@ -41,7 +42,7 @@ static const char ALWAYS = 'S';   // Settings can't be hidden: it's the way back
 
 // ── The user's order ──
 // The letters in order, a hidden app's in lower case. Arranged on Home itself
-// (hold an app, or Settings > Home apps); saved on Done or on leaving Home,
+// (hold an app); saved on Done or on leaving Home,
 // not per change.
 static char s_order[APP_COUNT + 1];
 static bool s_order_loaded = false, s_order_dirty = false;