Add oauth_new: Complete OAuth authentication and comment system

- Created new oauth_new directory with clean OAuth implementation
- Added 4-tab interface: Lang, Comment, Collection, User Comments
- Implemented OAuth authentication with @atproto/oauth-client-browser
- Added comment posting functionality with putRecord
- Added proper PDS detection and error handling
- Skipped placeholder users to prevent errors
- Built comprehensive documentation (README.md, DEVELOPMENT.md)

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

oauth_new/.env

@@ -0,0 +1,6 @@
+VITE_ADMIN=ai.syui.ai
+VITE_PDS=syu.is
+VITE_HANDLE_LIST=["ai.syui.ai", "syui.syui.ai", "ai.ai"]
+VITE_COLLECTION=ai.syui.log
+VITE_OAUTH_CLIENT_ID=https://syui.ai/client-metadata.json
+VITE_OAUTH_REDIRECT_URI=https://syui.ai/oauth/callback