feat: add configurable retention for aibridge (#20828)

Closes https://github.com/coder/internal/issues/1134

---------

Signed-off-by: Danny Kopping <danny@coder.com>

coderd/database/queries.sql.go

@@ -324,6 +324,49 @@ func (q *sqlQuerier) CountAIBridgeInterceptions(ctx context.Context, arg CountAI
 	return count, err
 }
 
+const deleteOldAIBridgeRecords = `-- name: DeleteOldAIBridgeRecords :one
+WITH
+  -- We don't have FK relationships between the dependent tables and aibridge_interceptions, so we can't rely on DELETE CASCADE.
+  to_delete AS (
+    SELECT id FROM aibridge_interceptions
+    WHERE started_at < $1::timestamp with time zone
+  ),
+  -- CTEs are executed in order.
+  tool_usages AS (
+    DELETE FROM aibridge_tool_usages
+    WHERE interception_id IN (SELECT id FROM to_delete)
+    RETURNING 1
+  ),
+  token_usages AS (
+    DELETE FROM aibridge_token_usages
+    WHERE interception_id IN (SELECT id FROM to_delete)
+    RETURNING 1
+  ),
+  user_prompts AS (
+    DELETE FROM aibridge_user_prompts
+    WHERE interception_id IN (SELECT id FROM to_delete)
+    RETURNING 1
+  ),
+  interceptions AS (
+    DELETE FROM aibridge_interceptions
+    WHERE id IN (SELECT id FROM to_delete)
+    RETURNING 1
+  )
+SELECT
+  (SELECT COUNT(*) FROM tool_usages) +
+  (SELECT COUNT(*) FROM token_usages) +
+  (SELECT COUNT(*) FROM user_prompts) +
+  (SELECT COUNT(*) FROM interceptions) as total_deleted
+`
+
+// Cumulative count.
+func (q *sqlQuerier) DeleteOldAIBridgeRecords(ctx context.Context, beforeTime time.Time) (int32, error) {
+	row := q.db.QueryRowContext(ctx, deleteOldAIBridgeRecords, beforeTime)
+	var total_deleted int32
+	err := row.Scan(&total_deleted)
+	return total_deleted, err
+}
+
 const getAIBridgeInterceptionByID = `-- name: GetAIBridgeInterceptionByID :one
 SELECT
 	id, initiator_id, provider, model, started_at, metadata, ended_at, api_key_id