fix(persistence): repair missing mcp readme column

src/langbot/pkg/persistence/alembic/versions/8f24d6c9b1a0_ensure_mcp_readme_column.py

@@ -0,0 +1,37 @@
+"""ensure mcp_servers readme column exists
+
+Revision ID: 8f24d6c9b1a0
+Revises: 7b2c1d9e4f30
+Create Date: 2026-06-13
+"""
+
+from alembic import op
+import sqlalchemy as sa
+
+
+revision = '8f24d6c9b1a0'
+down_revision = '7b2c1d9e4f30'
+branch_labels = None
+depends_on = None
+
+
+def _table_exists(table_name: str) -> bool:
+    return table_name in sa.inspect(op.get_bind()).get_table_names()
+
+
+def _column_exists(table_name: str, column_name: str) -> bool:
+    return column_name in {column['name'] for column in sa.inspect(op.get_bind()).get_columns(table_name)}
+
+
+def upgrade() -> None:
+    if not _table_exists('mcp_servers') or _column_exists('mcp_servers', 'readme'):
+        return
+    with op.batch_alter_table('mcp_servers', schema=None) as batch_op:
+        batch_op.add_column(sa.Column('readme', sa.Text(), nullable=False, server_default=''))
+
+
+def downgrade() -> None:
+    if not _table_exists('mcp_servers') or not _column_exists('mcp_servers', 'readme'):
+        return
+    with op.batch_alter_table('mcp_servers', schema=None) as batch_op:
+        batch_op.drop_column('readme')