Fix port 3389 conflict with xrdp - Add detection and resolution

[sprinteroz]

• Add port conflict detection in Prerequisites UI (SetupUI.vue)
• Implement checkRDPPort() function to detect xrdp and port usage (specs.ts)
• Update Specs type to include rdpPortAvailable and xrdpRunning fields (types.ts)
• Add comprehensive TROUBLESHOOTING.md with xrdp conflict solutions
• Add PORT_CONFLICT_FIX.md technical documentation for contributors
• Update FIX_WINBOAT.sh with port conflict checks and xrdp handling
• Update INSTALL_WINBOAT.sh with interactive xrdp resolution options
• Update setup_winboat_docker.sh with port conflict detection
• Add INSTALL_WINBOAT_1CLICK.sh: comprehensive installer with automatic conflict resolution

This addresses GitHub issue about port 3389 conflicts on Ubuntu 24.04 LTS with xrdp. Users are now proactively warned and guided to resolve conflicts before installation fails.

Fixes: Port 3389 'address already in use' error during WinBoat installation