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

backend/alembic/versions/e0f28e965fa5_add_agent_delete_confirmation.py

@@ -0,0 +1,35 @@
+"""add agent delete confirmation
+
+Revision ID: e0f28e965fa5
+Revises: cefef25d4634
+Create Date: 2026-02-04 16:55:33.389505
+
+"""
+from __future__ import annotations
+
+from alembic import op
+
+
+# revision identifiers, used by Alembic.
+revision = 'e0f28e965fa5'
+down_revision = 'cefef25d4634'
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.execute(
+        "ALTER TABLE agents ADD COLUMN IF NOT EXISTS delete_requested_at TIMESTAMP"
+    )
+    op.execute(
+        "ALTER TABLE agents ADD COLUMN IF NOT EXISTS delete_confirm_token_hash VARCHAR"
+    )
+
+
+def downgrade() -> None:
+    op.execute(
+        "ALTER TABLE agents DROP COLUMN IF EXISTS delete_confirm_token_hash"
+    )
+    op.execute(
+        "ALTER TABLE agents DROP COLUMN IF EXISTS delete_requested_at"
+    )