feat(agents): Add heartbeat configuration and delete confirmation for agents

backend/alembic/versions/cefef25d4634_ensure_heartbeat_config_column.py

@@ -0,0 +1,29 @@
+"""ensure heartbeat config column
+
+Revision ID: cefef25d4634
+Revises: 2b4c2f7b3eda
+Create Date: 2026-02-04 16:38:25.234627
+
+"""
+from __future__ import annotations
+
+from alembic import op
+
+
+# revision identifiers, used by Alembic.
+revision = 'cefef25d4634'
+down_revision = '2b4c2f7b3eda'
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.execute(
+        "ALTER TABLE agents ADD COLUMN IF NOT EXISTS heartbeat_config JSON"
+    )
+
+
+def downgrade() -> None:
+    op.execute(
+        "ALTER TABLE agents DROP COLUMN IF EXISTS heartbeat_config"
+    )