PCM build 236

🐛 Correzioni di bug

• reset decrypt_failures() on every load_profiles() call
• reject Mark/Space parity instead of crashing picocom
• stop leaking passwords via argv, fix host-key policy mismatch
• stop writing broken VNC password files
• honor per-session keepalive interval, fix env vars in external terminal
• fix broken success-path handling, add cert trust, real home dir, wire up multimon
• isolate per-profile decrypt failures, retry on wrong master password

🔧 Manutenzione

• unify the 3 divergent RDP argv builders into one