kin: KIN-126-frontend_dev

core/db.py

@@ -773,6 +773,12 @@ def _migrate(conn: sqlite3.Connection):
                 PRAGMA foreign_keys=ON;
             """)
 
+    # KIN-126: Add completed_at to tasks — set when task transitions to 'done'
+    task_cols_final = {r[1] for r in conn.execute("PRAGMA table_info(tasks)").fetchall()}
+    if "completed_at" not in task_cols_final:
+        conn.execute("ALTER TABLE tasks ADD COLUMN completed_at DATETIME DEFAULT NULL")
+        conn.commit()
+
 
 def _seed_default_hooks(conn: sqlite3.Connection):
     """Seed default hooks for the kin project (idempotent).

core/models.py

@@ -304,13 +304,15 @@ def list_tasks(
 
 
 def update_task(conn: sqlite3.Connection, id: str, **fields) -> dict:
-    """Update task fields. Auto-sets updated_at."""
+    """Update task fields. Auto-sets updated_at. Sets completed_at when status transitions to 'done'."""
     if not fields:
         return get_task(conn, id)
     json_cols = ("brief", "spec", "review", "test_result", "security_result", "labels")
     for key in json_cols:
         if key in fields:
             fields[key] = _json_encode(fields[key])
+    if "status" in fields and fields["status"] == "done":
+        fields["completed_at"] = datetime.now().isoformat()
     fields["updated_at"] = datetime.now().isoformat()
     sets = ", ".join(f"{k} = ?" for k in fields)
     vals = list(fields.values()) + [id]