feat(ui-lvgl): title bar with the clock, tidier controls, contextual nav bar

Density from less chrome instead of smaller rows (ROW_H stays 44):
- titled screens drop the status bar; the title bar (APPBAR_H) holds back,
  the title, the screen's actions and the time/battery on a pill; the status
  bar returns for Home, the map, typing, the quick panel and the lock
- one radius (RADIUS) for everything tapped: buttons, tabs, choices, chips
- tabs are all segmented at TAB_H in the body (GPS, Clock converted)
- Nodes: chips row + sort + status line become one toolbar row with
  Show / Order choices; Messages' All/Favourites is the same choice
- nav map: the target bar only while there is a target; the pin opens one
  "Places" popup; back from a map options page restores the map and Map
  tools as left, without a jump
- node detail actions at the top of the scroll; Home tiles fill the page
- rowsFit() leaves growing labels to the flex (a screen title cut to one
  letter after Messages' filter changed)

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

examples/companion_radio/ui-lvgl/GpsScreen.h

@@ -257,10 +257,9 @@ void UITask::buildGps() {
   s_cn0 = s_best = s_nmea = s_rx = s_d_fix = s_d_ttff = s_d_search = s_d_utc = nullptr;
   for (lv_obj_t*& p : s_sys_pill) p = nullptr;
   lv_obj_set_style_pad_row(body, 6, 0);
-  if (_header) {
+  {   // the tabs first under the title bar, as on every screen with tabs
     static const char* TABS[] = { "Sky", "Signal", "Details", "" };
-    lv_obj_t* tabs = segmented(_header, TABS, s_tab, 186, 28, theme::SURFACE);
-    lv_obj_align(tabs, LV_ALIGN_RIGHT_MID, -4, 0);
+    lv_obj_t* tabs = segmented(body, TABS, s_tab, LV_PCT(100), theme::TAB_H, theme::SURFACE);
     lv_obj_add_event_cb(tabs, onGpsTab, LV_EVENT_VALUE_CHANGED, NULL);
   }