[EPAC-2152]: add lobbyist organization endpoints

[riddim-developer-bot]

Scope

• Adds GET /lobbying/organizations and /api/v1/lobbying/organizations directory handling with search, sector filtering, communication-volume sorting, and paging.
• Adds GET /lobbying/organizations/{id} and /api/v1/lobbying/organizations/{id} profile handling with OCL citation/source metadata, lobbyists, subject matters, communication trend, and top DPOHs.
• Documents the routes in deployment manifest and OpenAPI, and updates the use-case catalog for the new REST adapters.

Bugfix SPEC

• Spec: N/A - feature issue, not a bug fix.
• Trace ID: N/A

Testing notes

• Automated tests run:
  • cd backend/lobbying && go test ./...
  • cd backend/openapi && go test ./...
  • python3 -m json.tool backend/openapi/openapi.json >/tmp/epac-openapi-check.json && python3 -m json.tool backend/manifest/deployment-services.json >/tmp/epac-deploy-services-check.json
  • scripts/check-boundaries.sh
• Manual verification: N/A - backend REST adapter only; no iOS UI surface in scope.

Screenshots

N/A - backend API only.

Related issue

• Closes: EPAC-2152
• https://linear.app/riddimsoftware/issue/EPAC-2152/browselobbyistorganizations-directory-profile-rest-endpoints-tests

Release-Note: Adds lobbyist organization directory and profile API endpoints backed by OCL data.