growqr-backend: route service sessions to workflows dashboard (#4)

## Summary

  This PR updates backend service-session orchestration so
  interview, roleplay, resume, and matchmaking flows integrate with
  the shipped `workflows--dashboard` frontend instead of the old
  GrowQR app demo UI.

  ## Changes

  - Added `WORKFLOWS_DASHBOARD_URL` config with fallback to
  `FRONTEND_ORIGIN`.
  - Updated service session URL generation to point to dashboard-
  owned routes:
    - `/v2/service-sessions/interview`
    - `/v2/service-sessions/roleplay`
    - `/v2/service-sessions/resume`
  - Preserved session query params, including `session_id`, service
  id, and user-facing metadata.
  - Updated chat route handling so returned service cards include
  dashboard session URLs.
  - Added/updated matchmaking service integration wiring.
  - Documented the dashboard-owned session route behavior in

  ## Validation

  - `npm run build` passed for `growqr-backend`.

Reviewed-on: puter/growqr-backend#4
Co-authored-by: NinjasPyajamas <divyansh242805@gmail.com>
Co-committed-by: NinjasPyajamas <divyansh242805@gmail.com>

agents/job-search.md

@@ -2,6 +2,7 @@
 id: job-search
 name: Job Search Agent
 role: Opportunity Scout
+service: matchmaking-service
 tools:
   - search_jobs
   - rank_opportunities