Add pagination (`?page=`/`?pageSize=`) to `GET /api/v1/anchors` in `routes/anchors.ts`

[Jagadeeshftw]

📌 Description

routes/anchors.ts's GET / supports ?status=, ?q=, ?sort=/?order=, and ?format=csv, but returns the entire filtered/sorted list with no pagination — unlike routes/settlements.ts, which already uses utils/pagination.ts's paginate helper. As the anchor registry grows, this list-everything behavior doesn't scale the same way settlements already handle it.

🧩 Requirements and context

• Wire utils/pagination.ts's paginate into GET /api/v1/anchors, applied after filtering and sorting, mirroring routes/settlements.ts's existing pattern.
• CSV export (?format=csv) should continue to ignore pagination and return every matching row, exactly as settlements' CSV export already does.
• Response shape should include a pagination object alongside anchors, matching the settlements route's { settlements, pagination } convention.

🛠️ Suggested execution

• Modify src/routes/anchors.ts's GET / handler to call paginate on the sorted list before building the JSON response (but after the ?format=csv branch, which returns early).
• Update src/openapi.ts's /api/v1/anchors GET parameters list to add page/pageSize.
• Add tests in src/routes/anchors.test.ts for paginated responses and for CSV export still returning all rows.

✅ Acceptance criteria

• GET /api/v1/anchors?page=2&pageSize=10 returns a pagination object and the correct slice.
• GET /api/v1/anchors?format=csv still returns every matching row regardless of page/pageSize.
• Existing anchors.test.ts filter/sort tests continue to pass alongside the new pagination behavior.

🔒 Security notes

N/A — read-path feature bringing anchors in line with settlements' existing pagination; no new data exposure.

📋 Guidelines

• Minimum 95% test coverage
• Clear documentation
• Timeframe: 96 hours