feat: add admin video jobs management endpoints and UI for listing, cancelling, and purging video jobs

Co-authored-by: Copilot <copilot@github.com>

backend/app/services/models.py

@@ -207,3 +207,40 @@ def get_cache_status(conn: duckdb.DuckDBPyConnection) -> dict[str, Any]:
     ).fetchone()
     last_updated, model_count = (row[0], row[1]) if row else (None, 0)
     return {"last_updated": last_updated, "model_count": model_count}
+
+
+def mark_timed_out_video_jobs(conn: duckdb.DuckDBPyConnection, timeout_minutes: int = 120) -> int:
+    """Mark video jobs that have been in 'queued' or 'processing' status for too long as 'failed'.
+
+    Returns the number of jobs marked as timed out.
+    """
+    timeout_threshold = datetime.now(
+        timezone.utc) - timedelta(minutes=timeout_minutes)
+
+    # Find timed out jobs
+    timed_out_rows = conn.execute(
+        """
+        SELECT id FROM generated_videos
+        WHERE status IN ('queued', 'processing')
+        AND updated_at < ?
+        """,
+        [timeout_threshold]
+    ).fetchall()
+
+    if not timed_out_rows:
+        return 0
+
+    job_ids = [row[0] for row in timed_out_rows]
+    placeholders = ",".join(["?"] * len(job_ids))
+
+    # Update them to failed
+    conn.execute(
+        f"""
+        UPDATE generated_videos
+        SET status = 'failed', updated_at = ?
+        WHERE id IN ({placeholders})
+        """,
+        [datetime.now(timezone.utc)] + job_ids
+    )
+
+    return len(job_ids)