feat: home screen ordering — reorder all screens from Settings

NodePrefs: add page_order[11] (1-indexed bit-index, 0=end/legacy).
DataStore: persist page_order appended after use_lemon_font.

UITask/HomeScreen:
- bitToPage(): maps stable bit indices 0-10 to HomePage enum values
- buildVisibleOrder(): respects page_order when initialised, else
  falls back to default enum sequence
- navPage() and navigation dots use buildVisibleOrder()

SettingsScreen Home Pages section:
- Add Settings (bit 9) and Messages (bit 10) — show as "always"
- LEFT/RIGHT on any home page item moves it earlier/later in order
- ENTER toggles ON/OFF for pages that can be disabled
- Position number shown before label once custom order is active
- ensurePageOrderInit() seeds default order on first reorder action

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

examples/companion_radio/DataStore.cpp

@@ -289,6 +289,9 @@ void DataStore::loadPrefsInt(const char *filename, NodePrefs& _prefs, double& no
                                     file.read((uint8_t *)&_prefs.clock_12h, sizeof(_prefs.clock_12h));
                                     if (file.available()) {
                                       file.read((uint8_t *)&_prefs.use_lemon_font, sizeof(_prefs.use_lemon_font));
+                                      if (file.available()) {
+                                        file.read((uint8_t *)_prefs.page_order, sizeof(_prefs.page_order));
+                                      }
                                     }
                                   }
                                 }
@@ -383,6 +386,7 @@ void DataStore::savePrefs(const NodePrefs& _prefs, double node_lat, double node_
     file.write((uint8_t *)&_prefs.auto_lock, sizeof(_prefs.auto_lock));
     file.write((uint8_t *)&_prefs.clock_12h, sizeof(_prefs.clock_12h));
     file.write((uint8_t *)&_prefs.use_lemon_font, sizeof(_prefs.use_lemon_font));
+    file.write((uint8_t *)_prefs.page_order, sizeof(_prefs.page_order));
 
     file.close();
   }