feat(contacts): channel favourites — filter in Settings + context menu

Add per-channel favourite marking and a Settings filter (all/fav) for
the channel list, symmetric with the existing DM and Room filters.

NodePrefs:
- ch_fav_bitmask (uint64_t): bit i = channel i is marked favourite
- ch_fav_only (uint8_t): 0=show all channels, 1=favourites only
- SCHEMA_SENTINEL bumped to 0xC0DE0005

DataStore: save/load both new fields before the sentinel.

SettingsScreen: new CH_FILTER item ('Channels: all/fav') in the
Contacts section, positioned between DM_FILTER and ROOM_FILTER.

QuickMsgScreen:
- buildChannelList() skips non-favourite channels when ch_fav_only=1
- Channel context menu gains a 4th option 'Fav'/'Unfav' that toggles
  ch_fav_bitmask for the selected channel and rebuilds the list

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

examples/companion_radio/NodePrefs.h

@@ -105,11 +105,14 @@ struct NodePrefs {  // persisted to file
   uint8_t trail_min_delta_idx;  // indexes TrailStore::minDeltaMeters (5/10/25/100 m)
   uint8_t trail_units_idx;      // indexes TrailStore::unitLabel (km/h, mph, min/km, min/mi)
 
+  uint64_t ch_fav_bitmask;      // bit i = channel i is marked as favourite
+  uint8_t  ch_fav_only;         // 0=show all channels (default), 1=show favourites only
+
   // Tail sentinel written at the end of /new_prefs. Bump the low byte when
   // adding/removing/reordering fields in DataStore::savePrefs/loadPrefsInt so
   // older saves are detected on load and skipped (zero-init defaults kept).
   // High 24 bits identify the file format; low byte is the schema revision.
-  static const uint32_t SCHEMA_SENTINEL = 0xC0DE0004;
+  static const uint32_t SCHEMA_SENTINEL = 0xC0DE0005;
 
   // Bit-index for each home page. Used by page_order (entries store bit+1) and
   // by home_pages_mask. Single source of truth — both HomeScreen::pageBit/bitToPage

examples/companion_radio/ui-new/QuickMsgScreen.h

@@ -47,6 +47,7 @@ class QuickMsgScreen : public UIScreen {
   char      _ctx_notif_item[22];
   char      _ctx_melody_item[20];
   char      _ctx_pin_item[28];   // "Pin to dial" or "Unpin (slot N)"
+  char      _ctx_ch_fav_item[12]; // "Fav" or "Unfav"
   char      _pin_slot_labels[NodePrefs::FAVOURITES_COUNT][22];  // per-slot picker labels
   bool      _pin_picker_active;  // true while the slot-picker submenu is open
   bool      _dm_direct_entry;    // entered DM_HIST via Favourites shortcut; CANCEL returns home
@@ -271,14 +272,16 @@ class QuickMsgScreen : public UIScreen {
   }
 
   void buildChannelList() {
+    NodePrefs* p = _task->getNodePrefs();
+    bool fav_only = (p && p->ch_fav_only);
     _num_channels = 0;
     for (int i = 0; i < MAX_GROUP_CHANNELS; i++) {
       ChannelDetails ch;
-      if (the_mesh.getChannel(i, ch) && ch.name[0] != '\0') {
+      if (!the_mesh.getChannel(i, ch) || ch.name[0] == '\0') continue;
+      if (fav_only && !(p->ch_fav_bitmask & (1ULL << i))) continue;
       _channel_indices[_num_channels++] = (uint8_t)i;
     }
   }
-  }
 
   // Returns per-channel notification state: 0=follow global, 1=muted, 2=force-on
   uint8_t chNotifState(uint8_t ch_idx) const {
@@ -1083,10 +1086,19 @@ public:
             uint8_t nstate = chNotifState(ch_idx);
             setChNotifState(ch_idx, (nstate + 1) % 3);
             _ctx_dirty = true;
-          } else {
+          } else if (_ctx_menu.selectedIndex() == 2) {
             uint8_t slot = chNotifMelody(ch_idx);
             setChNotifMelody(ch_idx, (slot + 1) % 3);
             _ctx_dirty = true;
+          } else {
+            // Toggle favourite
+            NodePrefs* p2 = _task->getNodePrefs();
+            if (p2) {
+              p2->ch_fav_bitmask ^= (1ULL << ch_idx);
+              _ctx_dirty = true;
+              buildChannelList();  // refilter if ch_fav_only is active
+              if (_channel_sel >= _num_channels) _channel_sel = _num_channels > 0 ? _num_channels - 1 : 0;
+            }
           }
         }
         if (res != PopupMenu::NONE && _ctx_dirty) {
@@ -1124,10 +1136,14 @@ public:
         { static const char* ML[] = { "global", "M1", "M2" };
           snprintf(_ctx_melody_item, sizeof(_ctx_melody_item), "Melody: %s",
                    ML[chNotifMelody(ch_idx)]); }
-        _ctx_menu.begin("Channel options", 3);
+        { NodePrefs* p2 = _task->getNodePrefs();
+          bool is_fav = p2 && (p2->ch_fav_bitmask & (1ULL << ch_idx));
+          snprintf(_ctx_ch_fav_item, sizeof(_ctx_ch_fav_item), is_fav ? "Unfav" : "Fav"); }
+        _ctx_menu.begin("Channel options", 4);
         _ctx_menu.addItem("Mark all read");
         _ctx_menu.addItem(_ctx_notif_item);
         _ctx_menu.addItem(_ctx_melody_item);
+        _ctx_menu.addItem(_ctx_ch_fav_item);
         _ctx_dirty = false;
         return true;
       }

examples/companion_radio/ui-new/SettingsScreen.h

@@ -57,7 +57,7 @@ class SettingsScreen : public UIScreen {
     TIMEZONE,
     LOW_BAT,
     // Contacts section
-    SECTION_CONTACTS, DM_FILTER, ROOM_FILTER,
+    SECTION_CONTACTS, DM_FILTER, CH_FILTER, ROOM_FILTER,
     // Messages section
     SECTION_MESSAGES,
     MSG_SLOT_0, MSG_SLOT_1, MSG_SLOT_2, MSG_SLOT_3, MSG_SLOT_4,
@@ -533,6 +533,10 @@ class SettingsScreen : public UIScreen {
       display.print("DM");
       display.setCursor(display.valCol(), y);
       display.print((p && p->dm_show_all) ? "all" : "fav");
+    } else if (item == CH_FILTER) {
+      display.print("Channels");
+      display.setCursor(display.valCol(), y);
+      display.print((p && p->ch_fav_only) ? "fav" : "all");
     } else if (item == ROOM_FILTER) {
       display.print("Rooms");
       display.setCursor(display.valCol(), y);
@@ -783,6 +787,11 @@ public:
       _dirty = true;
       return true;
     }
+    if (_selected == CH_FILTER && p && (left || right || enter)) {
+      p->ch_fav_only = p->ch_fav_only ? 0 : 1;
+      _dirty = true;
+      return true;
+    }
     if (_selected == ROOM_FILTER && p && (left || right || enter)) {
       p->room_fav_only = p->room_fav_only ? 0 : 1;
       _dirty = true;