[management,client] 0.75.0 release with new desktop UI (#6473)

- **Wails v3 application** (`client/ui`) with a React + TypeScript + Tailwind frontend replacing the Fyne UI: main connection view, exit-node switcher, networks/peers browser with detail panels, profile management, settings (general, network, SSH, security, troubleshooting, appearance), debug-bundle creation, and a first-run welcome flow.
- **Internationalization**: go-i18n bundle with 9 locales (en, de, es, fr, hu, it, pt, ru, zh-CN) shared between the tray and the frontend.
- **New system tray** implementation with per-platform theme-aware icons, including a native XEmbed host for Linux (`xembed_tray_linux.c`) and a Linux theme watcher.
- **Session handling**: auth session watcher (`client/internal/auth/sessionwatch`), pending login flow, session-expiration dialog and tray notifications, and `netbird login` improvements.
- **Daemon API extensions** (`daemon.proto`): status stream subscription, event stream, networks/exit-node selection endpoints, and richer full status — with probe throttling on the daemon side to protect against UI-driven request storms.
- **UI preferences store** persisted per profile, autostart management via the daemon (single source of truth in HKCU on Windows).
- **Build system**: Taskfile-based builds per platform (macOS, Linux, Windows), Docker cross-compilation images, MSIX/NSIS/nfpm/AppImage packaging, and a new `frontend-ui` CI workflow.

Co-authored-by: Zoltan Papp <zoltan.pmail@gmail.com>
Co-authored-by: Eduard Gert <kontakt@eduardgert.de>
Co-authored-by: braginini <bangvalo@gmail.com>
Co-authored-by: Pascal Fischer <32096965+pascal-fischer@users.noreply.github.com>
Co-authored-by: riccardom <riccardomanfrin@gmail.com>

client/mdm/canonical_loaders.go

@@ -15,6 +15,7 @@ var allKeys = []string{
 	KeyDisableUpdateSettings,
 	KeyDisableProfiles,
 	KeyDisableNetworks,
+	KeyDisableAdvancedView,
 	KeyDisableClientRoutes,
 	KeyDisableServerRoutes,
 	KeyBlockInbound,

client/mdm/policy.go

@@ -24,6 +24,13 @@ const (
 	KeyDisableUpdateSettings    = "disableUpdateSettings"
 	KeyDisableProfiles          = "disableProfiles"
 	KeyDisableNetworks          = "disableNetworks"
+	// KeyDisableAdvancedView gates the advanced-view section in the
+	// upcoming UI revision. UI-only: NOT stored on Config, not
+	// applied by applyMDMPolicy, not rejectable via SetConfig. The
+	// daemon surfaces it through GetFeatures (tristate: present
+	// true / present false / absent) and the same key appears in
+	// GetConfigResponse.mDMManagedFields when set.
+	KeyDisableAdvancedView      = "disableAdvancedView"
 	KeyDisableClientRoutes      = "disableClientRoutes"
 	KeyDisableServerRoutes      = "disableServerRoutes"
 	KeyBlockInbound             = "blockInbound"