Enable static site deployment with OAuth callback support

- Update OAuth callbacks to use query parameters instead of path routing
- Change redirect URIs to use current page URL (works with any base path)
- Add callback type prefix to state parameter (inference: or mcp:)
- Update App.tsx to route OAuth callbacks based on query params
- Add base path configuration to vite.config.ts for GitHub Pages
- Now works with static hosting (GitHub Pages, python http.server, etc)

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

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

vite.config.ts

@@ -5,6 +5,9 @@ import path from 'path'
 // https://vitejs.dev/config/
 export default defineConfig({
   plugins: [react()],
+  // Set base to '/' for local testing, or to your repo name for GitHub Pages
+  // e.g., base: '/example-remote-client/' for https://username.github.io/example-remote-client/
+  base: '/',
   resolve: {
     alias: {
       '@': path.resolve(__dirname, './src'),