Feature: voyage ai embedding support

[loc4atnt]

I've added Voyage AI embedding support and some guidance for the embedding config in the README file

[tirth8205]

Thanks for adding Voyage AI support — the embedding provider changes look reasonable! However, this PR has some issues that prevent merging:

1. Deletes CLAUDE.md (-107 lines) — this is essential project config
2. Deletes uv.lock (-3,370 lines) — this is our lockfile
3. Commits spec documents under specs/ — these shouldn't be in the repo

If you'd like to resubmit, please create a clean PR that only includes the Voyage AI embedding changes in embeddings.py (and matching tests). Happy to review that!

[tirth8205]

Voyage AI embedding support is not in main — embeddings.py only has local (sentence-transformers), Google Gemini, and MiniMax providers. Worth reviving if the implementation quality is good. However, note that this PR has 951 additions and 3492 deletions which is unusual — the deletions count may indicate it touched a lot of existing code. Recommend reviewing the diff carefully before reopening.