refactor: consolidate bot event routing

src/langbot/pkg/persistence/alembic/versions/0009_migrate_routing_to_event_bindings.py

@@ -16,6 +16,16 @@ down_revision = '0008_agent_product_surface'
 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:
+    if not _table_exists(table_name):
+        return False
+    return column_name in {column['name'] for column in sa.inspect(op.get_bind()).get_columns(table_name)}
+
+
 def _rule_to_filters(rule: dict) -> list[dict] | None:
     """Convert a pipeline_routing_rule to event_binding filters (best effort).
 
@@ -38,6 +48,11 @@ def _rule_to_filters(rule: dict) -> list[dict] | None:
 
 
 def upgrade() -> None:
+    if not _table_exists('bots') or not _column_exists('bots', 'event_bindings'):
+        return
+    if not _column_exists('bots', 'use_pipeline_uuid') or not _column_exists('bots', 'pipeline_routing_rules'):
+        return
+
     bind = op.get_bind()
     rows = bind.execute(
         sa.text('SELECT uuid, use_pipeline_uuid, pipeline_routing_rules, event_bindings FROM bots')

src/langbot/pkg/persistence/alembic/versions/0011_drop_legacy_bot_routing.py

@@ -0,0 +1,55 @@
+"""drop legacy bot pipeline routing columns
+
+Revision ID: 0011_drop_legacy_bot_routing
+Revises: 0010_merge_mcp_resource_agent_heads
+Create Date: 2026-07-01
+"""
+
+from alembic import op
+import sqlalchemy as sa
+
+
+revision = '0011_drop_legacy_bot_routing'
+down_revision = '0010_merge_mcp_resource_agent_heads'
+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:
+    if not _table_exists(table_name):
+        return False
+    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('bots'):
+        return
+    existing_columns = {column['name'] for column in sa.inspect(op.get_bind()).get_columns('bots')}
+    columns_to_drop = [
+        column_name
+        for column_name in ('use_pipeline_name', 'use_pipeline_uuid', 'pipeline_routing_rules')
+        if column_name in existing_columns
+    ]
+    if not columns_to_drop:
+        return
+
+    with op.batch_alter_table('bots', schema=None) as batch_op:
+        for column_name in columns_to_drop:
+            batch_op.drop_column(column_name)
+
+
+def downgrade() -> None:
+    if not _table_exists('bots'):
+        return
+
+    with op.batch_alter_table('bots', schema=None) as batch_op:
+        if not _column_exists('bots', 'use_pipeline_name'):
+            batch_op.add_column(sa.Column('use_pipeline_name', sa.String(255), nullable=True))
+        if not _column_exists('bots', 'use_pipeline_uuid'):
+            batch_op.add_column(sa.Column('use_pipeline_uuid', sa.String(255), nullable=True))
+        if not _column_exists('bots', 'pipeline_routing_rules'):
+            batch_op.add_column(sa.Column('pipeline_routing_rules', sa.JSON(), nullable=False, server_default='[]'))