Add Auto-Reply Bot and Tools screen to home carousel

- New 'Tools' page on the home screen carousel with Ringtone Editor and Auto-Reply Bot items
- Bot settings: enable/disable toggle, channel picker, trigger phrase, reply text (keyboard with pre-fill)
- Bot logic in MyMesh: case-insensitive substring match, 10 s cooldown to prevent reply loops
- Settings: Home Pages visibility control (which carousel pages are shown; Settings and Messages always visible)
- DataStore: persist home_pages_mask and bot fields with backward-compat guards on read

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

examples/companion_radio/ui-new/UITask.h

@@ -57,6 +57,7 @@ class UITask : public AbstractUITask {
   UIScreen* quick_msg;
   UIScreen* tools_screen;
   UIScreen* ringtone_edit;
+  UIScreen* bot_screen;
   UIScreen* curr;
 
   void userLedHandler();
@@ -88,6 +89,7 @@ public:
   void gotoQuickMsgScreen();
   void gotoToolsScreen();
   void gotoRingtoneEditor();
+  void gotoBotScreen();
   void playMelody(const char* melody);
   void stopMelody();
   bool isMelodyPlaying();