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

backend/alembic/versions/2b4c2f7b3eda_add_agent_heartbeat_config_column.py

@@ -0,0 +1,27 @@
+"""add agent heartbeat config column
+
+Revision ID: 2b4c2f7b3eda
+Revises: 69858cb75533
+Create Date: 2026-02-04 16:36:55.587762
+
+"""
+from __future__ import annotations
+
+from alembic import op
+
+
+# revision identifiers, used by Alembic.
+revision = '2b4c2f7b3eda'
+down_revision = '69858cb75533'
+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")