Fix RDP page buttons not working

- Added complete keyboard and mouse event handling from example.html
- Implemented Keyboard, EmulatedKeyboard, and UnicodeKeyboard classes
- Added mouse event handlers for movement, clicks, and wheel
- Added proper WebAssembly module loading with async/await
- Added missing constants (KeyAcquire, KeyRelease, SyncFlags)
- Fixed event listener attachments for canvas and input focus
- RDP page should now respond to user interactions