fix(web): paginate admin table fetches to avoid 422 limits

[aa-parky]

Summary

• add paginated table fetch support in the admin API client (getAllTableRows)
• clamp single-table fetch limit to API bounds (<=1000) in getTableRows
• update Accounts/Characters/Tombstones/Users metadata loaders to use paged fetches

Problem

Admin pages requested oversized table limits (2000, 3000, 4000) against /admin/database/table/{table} where backend validation enforces limit <= 1000, causing repeated 422 Unprocessable Entity responses.

Fix

• src/mud_server/web/static/js/api.js
  • getTableRows: normalize/clamp limit and offset
  • getAllTableRows: fetch all pages in batches of up to 1000
• src/mud_server/web/static/js/pages/accounts.js
• src/mud_server/web/static/js/pages/characters.js
• src/mud_server/web/static/js/pages/tombstones.js
• src/mud_server/web/static/js/pages/users_data.js

Testing

• node --check src/mud_server/web/static/js/api.js
• node --check src/mud_server/web/static/js/pages/accounts.js
• node --check src/mud_server/web/static/js/pages/characters.js
• node --check src/mud_server/web/static/js/pages/tombstones.js
• node --check src/mud_server/web/static/js/pages/users_data.js
• pytest tests/test_web/test_web_routes.py -q

Checklist

• No CI workflow or test-tag semantics changed.
• Required checks contract preserved: ci / All Checks Passed, ci / Secret Scan (Gitleaks).