fix(migrations): Merge auto heartbeat governor heads

Add a merge revision so the cherry-picked governor migrations coexist\nwith the newer master migration chain. This keeps alembic upgrade\nhead working from the current repository state.

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

backend/migrations/versions/e474bac07e41_merge_auto_heartbeat_governor_heads.py

@@ -0,0 +1,22 @@
+"""merge auto heartbeat governor heads
+
+Revision ID: e474bac07e41
+Revises: 1c3a2b7d9e10, a9b1c2d3e4f7
+Create Date: 2026-03-08 00:23:13.457926
+
+"""
+from __future__ import annotations
+
+# revision identifiers, used by Alembic.
+revision = 'e474bac07e41'
+down_revision = ('1c3a2b7d9e10', 'a9b1c2d3e4f7')
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    pass
+
+
+def downgrade() -> None:
+    pass