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/src/config/env.js

@@ -0,0 +1,17 @@
+// Environment configuration
+export const env = {
+  admin: import.meta.env.VITE_ADMIN,
+  pds: import.meta.env.VITE_PDS,
+  collection: import.meta.env.VITE_COLLECTION,
+  handleList: (() => {
+    try {
+      return JSON.parse(import.meta.env.VITE_HANDLE_LIST || '[]')
+    } catch {
+      return []
+    }
+  })(),
+  oauth: {
+    clientId: import.meta.env.VITE_OAUTH_CLIENT_ID,
+    redirectUri: import.meta.env.VITE_OAUTH_REDIRECT_URI
+  }
+}