refactor(agent): remove enabled state

src/langbot/pkg/persistence/alembic/versions/0023_drop_agent_enabled.py

@@ -0,0 +1,37 @@
+"""Drop the obsolete Agent enabled state.
+
+Revision ID: 0023_drop_agent_enabled
+Revises: 0022_merge_agent_reasoning_heads
+Create Date: 2026-08-25
+"""
+
+from __future__ import annotations
+
+from alembic import op
+import sqlalchemy as sa
+
+
+revision = '0023_drop_agent_enabled'
+down_revision = '0022_merge_agent_reasoning_heads'
+branch_labels = None
+depends_on = None
+
+
+def _column_exists(inspector: sa.Inspector, table_name: str, column_name: str) -> bool:
+    if table_name not in inspector.get_table_names():
+        return False
+    return any(column['name'] == column_name for column in inspector.get_columns(table_name))
+
+
+def upgrade() -> None:
+    inspector = sa.inspect(op.get_bind())
+    if _column_exists(inspector, 'agents', 'enabled'):
+        with op.batch_alter_table('agents') as batch_op:
+            batch_op.drop_column('enabled')
+
+
+def downgrade() -> None:
+    inspector = sa.inspect(op.get_bind())
+    if 'agents' in inspector.get_table_names() and not _column_exists(inspector, 'agents', 'enabled'):
+        with op.batch_alter_table('agents') as batch_op:
+            batch_op.add_column(sa.Column('enabled', sa.Boolean(), nullable=False, server_default=sa.true()))