PCM build 189

🆕 Nuove funzionalità

• plugin dialog pages + RDP domain in Connection tab
• password visibility toggle button (eye icon) in session dialog
• plugin system, cloud protocols, TOTP/2FA, templates, tags, SSH gateway, password gen
• build AppImage via GitHub Actions on release publish

🔧 Manutenzione

• collapse extra fields into expander for cleaner Connection tab