refactor: shared text-entry popup (ui-lvgl) and chat bubble row (ui-new); GPS search clock keeps a found fix

- ui-lvgl: navTextEntry()/TextEntry replace eight copies of popup + field +
  keyboard wiring; one byte-capped insert callback instead of two.
- ui-new: drawHeadedBubble()/BubbleMark replace the duplicated DM and channel
  bubble drawing in MessagesScreen.
- GpsSky::halt(): stopping the receiver ends an unfinished search but keeps
  the first-fix time; keyboard cursor blink restarts after a key.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VeBrxKyHHxWsmttVkUdBrj

examples/companion_radio/ui-lvgl/UITask.cpp

@@ -1056,6 +1056,15 @@ static void fieldFocus(lv_obj_t* ta, bool on) {
   lv_textarea_set_cursor_pos(ta, lv_textarea_get_cursor_pos(ta));
 }
 
+// A field limited in UTF-8 bytes (user data: the cap) -- names and other text
+// that is stored in a fixed buffer. LVGL's own limit counts characters.
+static void onByteCapInsert(lv_event_t* e) {
+  lv_obj_t* ta = (lv_obj_t*)lv_event_get_target(e);
+  const char* ins = (const char*)lv_event_get_param(e);
+  size_t cap = (size_t)(uintptr_t)lv_event_get_user_data(e);
+  if (ins && strlen(lv_textarea_get_text(ta)) + strlen(ins) > cap) lv_textarea_set_insert_replace(ta, "");
+}
+
 // The primary action of a screen or popup: full amber, dark text (Theme.h);
 // call after its label is made.
 static void stylePrimary(lv_obj_t* b) {