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

src/helpers/sensors/GpsSky.h

@@ -56,6 +56,10 @@ public:
     _len = 0;
   }
 
+  // The receiver was switched off: a search that never ended stops counting
+  // (a fix already found keeps its time-to-first-fix to look at).
+  void halt() { if (!ttff_ms) start_ms = 0; }
+
   void feed(char c) {
     if (c == '$') { _len = 0; _buf[_len++] = c; return; }
     if (_len == 0) return;

src/helpers/sensors/MicroNMEALocationProvider.h

@@ -105,7 +105,7 @@ public :
 
     void stop() override {
 #ifdef GPS_SKYVIEW
-        _sky.reset();   // a receiver that is off is not searching: stop the TTFF clock
+        _sky.halt();   // a receiver that is off is not searching: stop the search clock
 #endif
         if (_pin_en != -1) {
             digitalWrite(_pin_en, !GPS_EN_ACTIVE);