## Summary
Adds ownership/access checks before updating or deleting documents,
setting document metadata, and reading file contents from storage. Also
adds tests for authorized and unauthorized access paths.
### What problem does this PR solve?
Implement OpenAI chat completions in GO
POST /api/v1/openai/<chat_id>/chat/completions
OpenAI chat cli: internal/development.md
### Type of change
- [x] Refactoring
