feat(ui-lvgl): LVGL 9 skeleton frontend for Wio Tracker L2

New examples/companion_radio/ui-lvgl/ over the shared UI Core (env
Wio_Tracker_L2_companion_solo_lvgl, LVGL 9.2.2, pool in PSRAM):
status bar, home (clock, unread), conversation list (channels + recent
DMs with unread badges), contact picker, conversation view with bubbles,
delivery / relay markers and on-screen keyboard, toasts for Core events,
display auto-off with wake on touch / button. Board glue (LovyanGFX
flush + GT911 touch) isolated in LvglPort.h; design tokens in Theme.h.

UiCore gains the first frontend actions, sendDirectText() and
sendChannelText(), and drives DM auto-resend + unread reconcile from its
own loop (removed from ui-new's loop). MessageHistory exposes newest-first
DM ring iteration and a public contactByPrefix().

Verified on L2 hardware: navigation, send/receive, sleep/wake.

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

examples/companion_radio/ui-new/UITask.cpp

@@ -2485,10 +2485,6 @@ void UITask::pollHallSensor() {
 void UITask::loop() {
   pollConnection();   // BLE link state -> hasConnection() (see UITaskBase)
   drainCoreEvents();  // react to what the Core filed during mesh processing (alerts, wake, sounds)
-  // Background delivery: resend pending on-device DMs whose ACK timed out, and
-  // finalise the ✗ marker — runs regardless of which screen is active.
-  ((MessagesScreen*)messages_screen)->tickDmResends();
-  _core->reconcileDMUnread();
 #if UI_HAS_JOYSTICK
   uint8_t joy_rot = _node_prefs ? _node_prefs->joystick_rotation : JOYSTICK_ROTATION;
   int ev = user_btn.check();