[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/internal/state.go

@@ -33,17 +33,34 @@ func CtxGetState(ctx context.Context) *contextState {
 }
 
 type contextState struct {
-	err    error
-	status StatusType
-	mutex  sync.Mutex
+	err      error
+	status   StatusType
+	mutex    sync.Mutex
+	onChange func()
+}
+
+// SetOnChange installs a callback fired after every successful Set. Used by
+// the daemon to wire the status recorder's notifyStateChange so any
+// state.Set in the connect/login paths pushes a fresh snapshot to
+// SubscribeStatus subscribers without each callsite having to opt in.
+// The callback runs outside the contextState mutex to avoid a lock-order
+// dependency with the recorder's stateChangeMux.
+func (c *contextState) SetOnChange(fn func()) {
+	c.mutex.Lock()
+	c.onChange = fn
+	c.mutex.Unlock()
 }
 
 func (c *contextState) Set(update StatusType) {
 	c.mutex.Lock()
-	defer c.mutex.Unlock()
-
 	c.status = update
 	c.err = nil
+	cb := c.onChange
+	c.mutex.Unlock()
+
+	if cb != nil {
+		cb()
+	}
 }
 
 func (c *contextState) Status() (StatusType, error) {
@@ -57,6 +74,17 @@ func (c *contextState) Status() (StatusType, error) {
 	return c.status, nil
 }
 
+// CurrentStatus returns the last status set via Set, ignoring any wrapped
+// error. Use when the status is needed for reporting purposes (e.g. the
+// status snapshot stream) and a transient wrapped error from a retry loop
+// shouldn't blank out the underlying status.
+func (c *contextState) CurrentStatus() StatusType {
+	c.mutex.Lock()
+	defer c.mutex.Unlock()
+
+	return c.status
+}
+
 func (c *contextState) Wrap(err error) error {
 	c.mutex.Lock()
 	defer c.mutex.Unlock()