修复：合并 alembic 两个 head(no-op merge 节点)

本分支的 guide_video_play_table 与 main 的 8e04cc13a211 都挂在
(comparison_user_created_idx, monitoring_audit_rbac, notification_table)
这三条线之上,合并 main 后并列成两个 head,`upgrade head` 会直接报
Multiple head revisions。加一个空的 merge 节点收成单 head,不改表结构。

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

alembic/versions/d9c03cc3ea07_merge_guide_video_and_main_alembic_heads.py

@@ -0,0 +1,26 @@
+"""merge guide_video and main alembic heads
+
+Revision ID: d9c03cc3ea07
+Revises: 8e04cc13a211, guide_video_play_table
+Create Date: 2026-07-23 22:57:40.998161
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision: str = 'd9c03cc3ea07'
+down_revision: Union[str, Sequence[str], None] = ('8e04cc13a211', 'guide_video_play_table')
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    pass
+
+
+def downgrade() -> None:
+    pass