fix: pass remote desktop protocol

[ZacharyZcR]

Summary

• preserve the selected RDP, VNC, or Telnet protocol in mobile session state
• pass the protocol to the Guacamole connection endpoint instead of falling back to host.connectionType
• persist and restore the protocol through cross-device open tabs
• keep session labels and duplicate numbering scoped to each remote protocol

This rebases and resolves the implementation from #32 onto dev-1.5.0. The original change is authored by Benjamin Tausend (TheDuffman85).

Verification

• npx tsc --noEmit
• npm run lint (0 errors; existing warnings only)
• npm run format:check
• npm run verify:android-network-security
• git diff --check

Fixes Termix-SSH/Support#791.
Supersedes #32.