[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/ui/process/process.go

@@ -1,38 +0,0 @@
-package process
-
-import (
-	"os"
-	"path/filepath"
-	"strings"
-
-	"github.com/shirou/gopsutil/v3/process"
-)
-
-func IsAnotherProcessRunning() (int32, bool, error) {
-	processes, err := process.Processes()
-	if err != nil {
-		return 0, false, err
-	}
-
-	pid := os.Getpid()
-	processName := strings.ToLower(filepath.Base(os.Args[0]))
-
-	for _, p := range processes {
-		if int(p.Pid) == pid {
-			continue
-		}
-
-		runningProcessPath, err := p.Exe()
-		// most errors are related to short-lived processes
-		if err != nil {
-			continue
-		}
-
-		runningProcessName := strings.ToLower(filepath.Base(runningProcessPath))
-		if runningProcessName == processName && isProcessOwnedByCurrentUser(p) {
-			return p.Pid, true, nil
-		}
-	}
-
-	return 0, false, nil
-}

client/ui/process/process_nonwindows.go

@@ -1,26 +0,0 @@
-//go:build !windows
-
-package process
-
-import (
-	"os"
-
-	"github.com/shirou/gopsutil/v3/process"
-	log "github.com/sirupsen/logrus"
-)
-
-func isProcessOwnedByCurrentUser(p *process.Process) bool {
-	currentUserID := os.Getuid()
-	uids, err := p.Uids()
-	if err != nil {
-		log.Errorf("get process uids: %v", err)
-		return false
-	}
-	for _, id := range uids {
-		log.Debugf("checking process uid: %d", id)
-		if int(id) == currentUserID {
-			return true
-		}
-	}
-	return false
-}

client/ui/process/process_windows.go

@@ -1,24 +0,0 @@
-package process
-
-import (
-	"os/user"
-
-	"github.com/shirou/gopsutil/v3/process"
-	log "github.com/sirupsen/logrus"
-)
-
-func isProcessOwnedByCurrentUser(p *process.Process) bool {
-	processUsername, err := p.Username()
-	if err != nil {
-		log.Errorf("get process username error: %v", err)
-		return false
-	}
-
-	currUser, err := user.Current()
-	if err != nil {
-		log.Errorf("get current user error: %v", err)
-		return false
-	}
-
-	return processUsername == currUser.Username
-}