Fix typeText sending lowercase keysym for uppercase letters (#9)
Over RFB, keysym-based key events are injected directly - the server
does not derive a shifted variant from a lowercase keysym. Return the
original uppercase scalar instead of its lowercased form so Shift+letter
produces the uppercase character.
Pace incremental framebuffer update requests to ~20/s
The message loop sent one update request per iteration (~440/s
measured), flooding the server's event loop and stalling its input
injection right after large screen changes - typed keys piled up
unread while the daemon kept reporting OK. Screenshots read the local
framebuffer, so the added <=50ms staleness is invisible to callers.