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/SoundScreen.h

@@ -99,7 +99,7 @@ static void rebuildStrip() {
     lv_obj_t* c = lv_button_create(s_strip);
     lv_obj_set_size(c, 38, 44);
     lv_obj_set_style_pad_all(c, 0, 0);
-    lv_obj_set_style_radius(c, theme::RADIUS_SM, 0);
+    lv_obj_set_style_radius(c, theme::RADIUS, 0);
     lv_obj_set_style_shadow_width(c, 0, 0);
     lv_obj_set_style_border_color(c, lv_color_hex(theme::ACCENT), 0);
     lv_obj_add_event_cb(c, onMelNote, LV_EVENT_CLICKED, (void*)(uintptr_t)i);
@@ -144,7 +144,7 @@ static lv_obj_t* smallButton(lv_obj_t* parent, const char* text, uint8_t act) {
   lv_obj_t* b = lv_button_create(parent);
   lv_obj_set_size(b, 40, 32);
   lv_obj_set_style_pad_all(b, 0, 0);
-  lv_obj_set_style_radius(b, theme::RADIUS_SM, 0);
+  lv_obj_set_style_radius(b, theme::RADIUS, 0);
   lv_obj_set_style_shadow_width(b, 0, 0);
   lv_obj_set_style_bg_color(b, lv_color_hex(theme::SURFACE_2), 0);
   lv_obj_add_event_cb(b, onMelAction, LV_EVENT_CLICKED, (void*)(uintptr_t)act);