feat(v3): migrate workspace to API, Tauri desktop, and v3 crates; remove legacy MCP stack

- Add apps/api, desktop Tauri shell, domain/application/crypto/device-auth/infrastructure-db
- Replace desktop-daemon vault integration; drop secrets-core and secrets-mcp*
- Ignore apps/desktop/dist and generated Tauri icons; document icon/dist steps in AGENTS.md
- Apply rustfmt; fix clippy (collapsible_if, HTTP method as str)

deploy/secrets-mcp.service

@@ -1,26 +1,26 @@
 [Unit]
-Description=Secrets MCP Server
+Description=Secrets API Server
 After=network.target
 Wants=network-online.target
 
 [Service]
 Type=simple
-User=secrets-mcp
-Group=secrets-mcp
-WorkingDirectory=/opt/secrets-mcp
-EnvironmentFile=/opt/secrets-mcp/.env
-ExecStart=/opt/secrets-mcp/secrets-mcp
+User=secrets
+Group=secrets
+WorkingDirectory=/opt/secrets
+EnvironmentFile=/opt/secrets/.env
+ExecStart=/opt/secrets/secrets-api
 Restart=always
 RestartSec=5
 StandardOutput=journal
 StandardError=journal
-SyslogIdentifier=secrets-mcp
+SyslogIdentifier=secrets-api
 
 # 安全加固
 NoNewPrivileges=yes
 ProtectSystem=strict
 ProtectHome=yes
-ReadWritePaths=/opt/secrets-mcp
+ReadWritePaths=/opt/secrets
 PrivateTmp=yes
 
 [Install]