Clean up orphaned contact child rows and add foreign key enforcement

app/migrations.py

@@ -353,6 +353,13 @@ async def run_migrations(conn: aiosqlite.Connection) -> int:
         await set_version(conn, 45)
         applied += 1
 
+    # Migration 46: Clean orphaned contact child rows left by old prefix promotion
+    if version < 46:
+        logger.info("Applying migration 46: clean orphaned contact child rows")
+        await _migrate_046_cleanup_orphaned_contact_child_rows(conn)
+        await set_version(conn, 46)
+        applied += 1
+
     if applied > 0:
         logger.info(
             "Applied %d migration(s), schema now at version %d", applied, await get_version(conn)
@@ -2773,3 +2780,91 @@ async def _migrate_045_rebuild_contacts_direct_route_columns(conn: aiosqlite.Con
     await conn.execute("DROP TABLE contacts")
     await conn.execute("ALTER TABLE contacts_new RENAME TO contacts")
     await conn.commit()
+
+
+async def _migrate_046_cleanup_orphaned_contact_child_rows(conn: aiosqlite.Connection) -> None:
+    """Move uniquely resolvable orphan contact child rows onto full contacts, drop the rest."""
+    existing_tables_cursor = await conn.execute("SELECT name FROM sqlite_master WHERE type='table'")
+    existing_tables = {row[0] for row in await existing_tables_cursor.fetchall()}
+    if "contacts" not in existing_tables:
+        await conn.commit()
+        return
+
+    child_tables = [
+        table
+        for table in ("contact_name_history", "contact_advert_paths")
+        if table in existing_tables
+    ]
+    if not child_tables:
+        await conn.commit()
+        return
+
+    orphan_keys: set[str] = set()
+
+    for table in child_tables:
+        cursor = await conn.execute(
+            f"""
+            SELECT DISTINCT child.public_key
+            FROM {table} child
+            LEFT JOIN contacts c ON c.public_key = child.public_key
+            WHERE c.public_key IS NULL
+            """
+        )
+        orphan_keys.update(row[0] for row in await cursor.fetchall())
+
+    for orphan_key in sorted(orphan_keys, key=len, reverse=True):
+        match_cursor = await conn.execute(
+            """
+            SELECT public_key
+            FROM contacts
+            WHERE length(public_key) = 64
+              AND public_key LIKE ? || '%'
+            ORDER BY public_key
+            """,
+            (orphan_key.lower(),),
+        )
+        matches = [row[0] for row in await match_cursor.fetchall()]
+        resolved_key = matches[0] if len(matches) == 1 else None
+
+        if resolved_key is not None:
+            if "contact_name_history" in child_tables:
+                await conn.execute(
+                    """
+                    INSERT INTO contact_name_history (public_key, name, first_seen, last_seen)
+                    SELECT ?, name, first_seen, last_seen
+                    FROM contact_name_history
+                    WHERE public_key = ?
+                    ON CONFLICT(public_key, name) DO UPDATE SET
+                        first_seen = MIN(contact_name_history.first_seen, excluded.first_seen),
+                        last_seen = MAX(contact_name_history.last_seen, excluded.last_seen)
+                    """,
+                    (resolved_key, orphan_key),
+                )
+            if "contact_advert_paths" in child_tables:
+                await conn.execute(
+                    """
+                    INSERT INTO contact_advert_paths
+                        (public_key, path_hex, path_len, first_seen, last_seen, heard_count)
+                    SELECT ?, path_hex, path_len, first_seen, last_seen, heard_count
+                    FROM contact_advert_paths
+                    WHERE public_key = ?
+                    ON CONFLICT(public_key, path_hex, path_len) DO UPDATE SET
+                        first_seen = MIN(contact_advert_paths.first_seen, excluded.first_seen),
+                        last_seen = MAX(contact_advert_paths.last_seen, excluded.last_seen),
+                        heard_count = contact_advert_paths.heard_count + excluded.heard_count
+                    """,
+                    (resolved_key, orphan_key),
+                )
+
+        if "contact_name_history" in child_tables:
+            await conn.execute(
+                "DELETE FROM contact_name_history WHERE public_key = ?",
+                (orphan_key,),
+            )
+        if "contact_advert_paths" in child_tables:
+            await conn.execute(
+                "DELETE FROM contact_advert_paths WHERE public_key = ?",
+                (orphan_key,),
+            )
+
+    await conn.commit()

app/repository/contacts.py

@@ -431,6 +431,43 @@ class ContactRepository:
 
         Returns the placeholder public keys that were merged into the full key.
         """
+
+        async def migrate_child_rows(old_key: str, new_key: str) -> None:
+            await db.conn.execute(
+                """
+                INSERT INTO contact_name_history (public_key, name, first_seen, last_seen)
+                SELECT ?, name, first_seen, last_seen
+                FROM contact_name_history
+                WHERE public_key = ?
+                ON CONFLICT(public_key, name) DO UPDATE SET
+                    first_seen = MIN(contact_name_history.first_seen, excluded.first_seen),
+                    last_seen = MAX(contact_name_history.last_seen, excluded.last_seen)
+                """,
+                (new_key, old_key),
+            )
+            await db.conn.execute(
+                """
+                INSERT INTO contact_advert_paths
+                    (public_key, path_hex, path_len, first_seen, last_seen, heard_count)
+                SELECT ?, path_hex, path_len, first_seen, last_seen, heard_count
+                FROM contact_advert_paths
+                WHERE public_key = ?
+                ON CONFLICT(public_key, path_hex, path_len) DO UPDATE SET
+                    first_seen = MIN(contact_advert_paths.first_seen, excluded.first_seen),
+                    last_seen = MAX(contact_advert_paths.last_seen, excluded.last_seen),
+                    heard_count = contact_advert_paths.heard_count + excluded.heard_count
+                """,
+                (new_key, old_key),
+            )
+            await db.conn.execute(
+                "DELETE FROM contact_name_history WHERE public_key = ?",
+                (old_key,),
+            )
+            await db.conn.execute(
+                "DELETE FROM contact_advert_paths WHERE public_key = ?",
+                (old_key,),
+            )
+
         normalized_full_key = full_key.lower()
         cursor = await db.conn.execute(
             """
@@ -467,6 +504,8 @@ class ContactRepository:
             if (match_row["match_count"] if match_row is not None else 0) != 1:
                 continue
 
+            await migrate_child_rows(old_key, normalized_full_key)
+
             if full_exists:
                 await db.conn.execute(
                     """