refactor: remove legacy file-based storage layer

dev: Apply feedback to multi-domain

hardening: redact exception detail in debug explain endpoint

dev: Feedback added to recommendation results

dev: additional user-kind filter in CMS

DEV: Debug -> Admin Dashboard with stats and user mgnt

dev: User role-gated Debug page access

hardening: unifying recommendation task IDs

dev: few harness strenthen

Adding timeout and rate limits

API Testing playground implemented

Centralised Unit Test registration entry