feat(i18n): add multi-language support (ja/ko/vi/ru/zh-TW) with system auto-detection

- Extend AppLanguage to 7 locales: zh-CN, zh-TW, en, ja, ko, vi, ru
- Auto-detect system language via navigator.languages; fallback to English
- Add BCP47 locale mapping for date formatting and sorting
- Create 50 translation JSON files (5 languages × 10 namespaces, 1137 keys each)
- Update language selector with native language names
- Extend locale key parity test to cover all 7 languages (70 assertions)
- Add VNC/RDP desktop, serial terminal, AI agent, port forwarding, and SFTP features
- Add credential encryption, host metrics, session backup crypto, and zmodem bridge
- Update Rust backend: desktop services, host metrics, SSH/SFTP enhancements

src-tauri/src/application/state.rs

@@ -1,8 +1,13 @@
 use std::sync::Arc;
 
 use crate::services::{
-    ai::AiService, deep_link::DeepLinkService, local_terminal::LocalTerminalService,
-    serial::SerialService, ssh::SshService, storage::StorageService,
+    ai::AiService,
+    deep_link::DeepLinkService,
+    desktop::{RdpService, VncService},
+    local_terminal::LocalTerminalService,
+    serial::SerialService,
+    ssh::SshService,
+    storage::StorageService,
 };
 
 /// Shared application root. Services are added here only after their lifecycle
@@ -13,6 +18,8 @@ pub struct AppState {
     pub deep_links: Arc<DeepLinkService>,
     pub local_terminal: Arc<LocalTerminalService>,
     pub serial: Arc<SerialService>,
+    pub rdp: Arc<RdpService>,
+    pub vnc: Arc<VncService>,
     pub ssh: Arc<SshService>,
     pub storage: Arc<StorageService>,
 }