DW bundle: security userId ownership validation (DW-103)
requested to merge bmad-loop/20260813-135551-e159/dw-security-userid-ownership into feat/opea-1.5-upgrade/prd
Trace MR created by bmad-loop story-track. Fixes DW-103: IDOR vulnerability — GET /query/:queryId/messages and GET /queries/:queryId/conversations lacked userId ownership validation.