(Fix): replaced the broken ForkExec (which relaunched the same binary with made-up flags) with a direct session.Spawn call that drops privileges and runs the desktop in-process.

src/main.go

@@ -19,6 +19,7 @@ import (
 	"latchd/auth"
 	"latchd/config"
 	"latchd/login"
+	"latchd/session"
 	"latchd/tui/bg"
 )
 
@@ -144,39 +145,27 @@ func spawnSession(res *login.Result) error {
 		return nil
 	}
 	log.Printf("spawning %s → %s (%s)", res.Username, res.Env.Title, res.Env.Kind)
+
 	creds, err := auth.Validate(res.Username, res.Password, res.Config.PAMService)
 	if err != nil {
 		return fmt.Errorf("auth: %w", err)
 	}
 	defer creds.CloseSession()
 
-	pid, err := syscall.ForkExec("/proc/self/exe", []string{
+	if err := creds.OpenSession(); err != nil {
-		"latchd-session",
+		return fmt.Errorf("pam session: %w", err)
-		"--user", creds.Username,
+	}
-		"--uid", fmt.Sprintf("%d", creds.UID),
+
-		"--gid", fmt.Sprintf("%d", creds.PrimaryGID),
+	sess, err := session.Spawn(&res.Env, creds.UID, creds.PrimaryGID, creds.AllGIDs, &res.Config)
-		"--home", creds.HomeDir,
-		"--shell", creds.Shell,
-		"--env-kind", res.Env.Kind,
-		"--env-exec", res.Env.XinitrcPath,
-		"--tty", fmt.Sprintf("%d", res.Config.TTY),
-	}, &syscall.ProcAttr{
-		Env:   os.Environ(),
-		Dir:   creds.HomeDir,
-		Files: []uintptr{0, 1, 2},
-		Sys:   &syscall.SysProcAttr{Setsid: true},
-	})
 	if err != nil {
-		return fmt.Errorf("fork: %w", err)
+		return fmt.Errorf("spawn: %w", err)
 	}
 
-	creds.OpenSession()
+	err = sess.Wait()
-
+	if err != nil {
-	var ws syscall.WaitStatus
+		log.Printf("session exited: %v", err)
-	if _, err := syscall.Wait4(pid, &ws, 0, nil); err != nil {
-		return fmt.Errorf("wait: %w", err)
 	}
-	log.Printf("session pid %d exited %d", pid, ws.ExitStatus())
+	log.Printf("session pid %d ended", sess.PID())
 	return nil
 }