fix(dm): refresh mc.contacts on approve, DB name fallback, relink orphans

Three fixes for DM sending after contact delete/re-add:

1. approve_contact() now calls ensure_contacts() to refresh mc.contacts
   so send_dm can find newly added contacts immediately

2. cli.send_dm() falls back to DB name lookup when mc.contacts misses,
   preventing the contact name from being passed as a pubkey string

3. approve_contact() re-links orphaned DMs (NULL contact_pubkey from
   ON DELETE SET NULL) back to the re-added contact

New DB methods: get_contact_by_name(), relink_orphaned_dms()

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

app/database.py

@@ -137,6 +137,15 @@ class Database:
             ).fetchone()
             return dict(row) if row else None
 
+    def get_contact_by_name(self, name: str) -> Optional[Dict]:
+        """Find a contact by exact name match."""
+        with self._connect() as conn:
+            row = conn.execute(
+                "SELECT * FROM contacts WHERE name = ? AND length(public_key) = 64 LIMIT 1",
+                (name,)
+            ).fetchone()
+            return dict(row) if row else None
+
     def delete_contact(self, public_key: str) -> bool:
         with self._connect() as conn:
             cursor = conn.execute(
@@ -373,6 +382,26 @@ class Database:
             ).fetchone()
             return dict(row) if row else None
 
+    def relink_orphaned_dms(self, public_key: str) -> int:
+        """Re-link DMs with NULL contact_pubkey back to this contact.
+
+        When a contact is deleted, ON DELETE SET NULL nullifies contact_pubkey.
+        When the contact is re-added, re-link those orphaned DMs.
+        Uses raw_json to match by pubkey_prefix.
+        """
+        public_key = public_key.lower()
+        prefix = public_key[:12]  # Short prefix used in pubkey_prefix field
+        with self._connect() as conn:
+            cursor = conn.execute(
+                """UPDATE direct_messages SET contact_pubkey = ?
+                   WHERE contact_pubkey IS NULL
+                   AND (raw_json LIKE ? OR raw_json IS NULL)""",
+                (public_key, f'%{prefix}%')
+            )
+            if cursor.rowcount > 0:
+                logger.info(f"Re-linked {cursor.rowcount} orphaned DMs to {public_key[:12]}...")
+            return cursor.rowcount
+
     def find_dm_duplicate(self, contact_pubkey: str, content: str,
                            sender_timestamp: int = None,
                            window_seconds: int = 300) -> Optional[Dict]:

app/device_manager.py

@@ -1167,6 +1167,10 @@ class DeviceManager:
                 return {'success': False, 'error': 'Contact not in pending list'}
 
             self.execute(self.mc.commands.add_contact(contact))
+
+            # Refresh mc.contacts so send_dm can find the new contact
+            self.execute(self.mc.ensure_contacts(follow=True))
+
             last_adv = contact.get('last_advert')
             last_advert_val = (
                 str(int(last_adv))
@@ -1182,6 +1186,9 @@ class DeviceManager:
                 last_advert=last_advert_val,
                 source='device',
             )
+            # Re-link orphaned DMs (from previous ON DELETE SET NULL)
+            self.db.relink_orphaned_dms(pubkey)
+
             # Remove from pending list after successful approval
             self.mc.pending_contacts.pop(pubkey, None)
             return {'success': True, 'message': 'Contact approved'}

app/meshcore/cli.py

@@ -376,15 +376,25 @@ def send_dm(recipient: str, text: str) -> Tuple[bool, Dict]:
 
     try:
         dm = _get_dm()
-        # Try to find contact by name first
+        recipient = recipient.strip()
+
+        # Try to find contact by name in mc.contacts (in-memory)
         contact = None
         if dm.mc:
-            contact = dm.mc.get_contact_by_name(recipient.strip())
+            contact = dm.mc.get_contact_by_name(recipient)
 
         if contact:
             pubkey = contact.get('public_key', recipient)
+        elif len(recipient) >= 12 and all(c in '0123456789abcdef' for c in recipient.lower()):
+            # Looks like a pubkey/prefix already
+            pubkey = recipient
         else:
-            pubkey = recipient.strip()
+            # Name not in mc.contacts — try DB lookup
+            db_contact = dm.db.get_contact_by_name(recipient)
+            if db_contact:
+                pubkey = db_contact['public_key']
+            else:
+                pubkey = recipient
 
         result = dm.send_dm(pubkey, text.strip())
         return result['success'], result