fix: refresh mc.contacts from device on dirty flag to update stale names

Contact names stayed stale indefinitely because mc.contacts (in-memory
dict) was only populated at startup. When a remote node renamed itself,
the device firmware updated its contact list but the app never re-read it.

Now ensure_contacts(follow=True) is called when contacts_dirty is set:
- In _on_advertisement(): refresh before name lookup (incremental via lastmod)
- In get_contacts_with_last_seen(): refresh + DB sync before serving API data

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

app/device_manager.py

@@ -778,7 +778,7 @@ class DeviceManager:
 
         ADVERTISEMENT payload only contains {'public_key': '...'}.
         Full contact details (name, type, lat/lon) must be looked up
-        from mc.contacts which is synced at startup.
+        from mc.contacts which is refreshed from device when dirty.
         If the contact is unknown (new auto-add by firmware), refresh contacts.
         """
         try:
@@ -788,6 +788,13 @@ class DeviceManager:
             if not pubkey:
                 return
 
+            # Refresh contacts from device if dirty (e.g., contact renamed).
+            # The meshcore library sets contacts_dirty=True on every advert,
+            # but with auto_update_contacts=False we must refresh manually.
+            # Uses incremental fetch (lastmod) so only changed contacts are read.
+            if self.mc.contacts_dirty:
+                await self.mc.ensure_contacts(follow=True)
+
             # Look up full contact details from meshcore's contact list
             contact = (self.mc.contacts or {}).get(pubkey, {})
             name = contact.get('adv_name', contact.get('name', ''))

app/meshcore/cli.py

@@ -158,10 +158,22 @@ def _parse_last_advert(value) -> int:
 
 
 def get_contacts_with_last_seen() -> Tuple[bool, Dict[str, Dict], str]:
-    """Get contacts actually on the device firmware (from mc.contacts)."""
+    """Get contacts actually on the device firmware (from mc.contacts).
+
+    Refreshes from device if contacts_dirty flag is set (e.g., after
+    receiving adverts that may carry updated names/paths).
+    """
     try:
         dm = _get_dm()
-        if not dm.mc or not dm.mc.contacts:
+        if not dm.mc:
+            return True, {}, ""
+
+        # Refresh contacts from device if dirty (name changes, path updates, etc.)
+        if dm.mc.contacts_dirty:
+            dm.execute(dm.mc.ensure_contacts(follow=True))
+            dm._sync_contacts_to_db()
+
+        if not dm.mc.contacts:
             return True, {}, ""
         contacts_dict = {}
         for pk, contact in dm.mc.contacts.items():