/claim #2807

Added a complete Coda.io connector for importing documents and pages into Onyx.

Features ✅ Full API integration with Coda.io ✅ Authentication via API tokens
✅ Fetches documents and pages ✅ Frontend configuration UI ✅ Proper error handling

Demo Video

https://www.loom.com/share/8a4511a546504e8993680472aabdcbaf

Testing Done

✅ API connection tested ✅ Document fetching verified ✅ All integration tests passing

Closes #2807

Summary by cubic

Adds a Coda.io import connector to index documents and pages, with a simple admin UI for token-based setup. Enables Coda as a data source and fulfills #2807.

• New Features

  • Backend CodaConnector with API token auth, pagination, retries, and batching (INDEX_BATCH_SIZE).
  • Converts Coda documents/pages into Onyx Documents with metadata and links; handles empty content safely.
  • Added CODA to DocumentSource and registry mapping for connector discovery.
  • Admin UI (CodaConnector.tsx) to enter and validate the API token (UUID format) with setup guidance.

• Bug Fixes

  • Removed hardcoded API tokens and cleaned up test files for security.

^{Written for commit e4223792491c82d9abab61338bf7d364accd4ff3. Summary will update automatically on new commits.}