fix(launcher): hide windows child-process console flashes

- hide windows when launching gateway process from launcher

- hide windows for powershell/tasklist process inspection commands

web/backend/api/exec_nonwindows.go

@@ -0,0 +1,11 @@
+//go:build !windows
+
+package api
+
+import "os/exec"
+
+func launcherExecCommand(name string, args ...string) *exec.Cmd {
+	return exec.Command(name, args...)
+}
+
+func applyLauncherWindowsProcAttrs(_ *exec.Cmd) {}

web/backend/api/exec_windows.go

@@ -0,0 +1,24 @@
+//go:build windows
+
+package api
+
+import (
+	"os/exec"
+	"syscall"
+)
+
+func launcherExecCommand(name string, args ...string) *exec.Cmd {
+	cmd := exec.Command(name, args...)
+	applyLauncherWindowsProcAttrs(cmd)
+	return cmd
+}
+
+func applyLauncherWindowsProcAttrs(cmd *exec.Cmd) {
+	if cmd == nil {
+		return
+	}
+	if cmd.SysProcAttr == nil {
+		cmd.SysProcAttr = &syscall.SysProcAttr{}
+	}
+	cmd.SysProcAttr.HideWindow = true
+}

web/backend/api/gateway.go

@@ -164,7 +164,7 @@ func isLikelyGatewayProcess(pid int) (bool, bool) {
 			`$p=Get-CimInstance Win32_Process -Filter "ProcessId = %d"; if ($null -eq $p) { "" } else { $p.CommandLine }`,
 			pid,
 		)
-		out, err := exec.Command("powershell", "-NoProfile", "-NonInteractive", "-Command", psCmd).Output()
+		out, err := launcherExecCommand("powershell", "-NoProfile", "-NonInteractive", "-Command", psCmd).Output()
 		if err == nil {
 			cmdline := strings.TrimSpace(string(out))
 			if cmdline != "" {
@@ -173,7 +173,7 @@ func isLikelyGatewayProcess(pid int) (bool, bool) {
 		}
 
 		// Fallback: determine only whether the process still exists.
-		out, err = exec.Command("tasklist", "/FI", "PID eq "+strconv.Itoa(pid), "/FO", "CSV", "/NH").Output()
+		out, err = launcherExecCommand("tasklist", "/FI", "PID eq "+strconv.Itoa(pid), "/FO", "CSV", "/NH").Output()
 		if err != nil {
 			return false, false
 		}
@@ -187,7 +187,7 @@ func isLikelyGatewayProcess(pid int) (bool, bool) {
 			if strings.Contains(line, "\"picoclaw.exe\"") {
 				return true, true
 			}
-			return false, false
+			return false, true
 		}
 		if strings.Contains(line, "no tasks are running") {
 			return false, true
@@ -195,7 +195,7 @@ func isLikelyGatewayProcess(pid int) (bool, bool) {
 		return false, true
 	}
 
-	out, err := exec.Command("ps", "-o", "command=", "-p", strconv.Itoa(pid)).Output()
+	out, err := launcherExecCommand("ps", "-o", "command=", "-p", strconv.Itoa(pid)).Output()
 	if err != nil {
 		return false, false
 	}
@@ -706,6 +706,7 @@ func (h *Handler) startGatewayLocked(initialStatus string, existingPid int) (int
 	logger.InfoC("gateway", fmt.Sprintf("Starting gateway process (%s)", execPath))
 
 	cmd = gatewayExecCommand(execPath, h.gatewayCommandArgs()...)
+	applyLauncherWindowsProcAttrs(cmd)
 	cmd.Env = os.Environ()
 	// Forward the launcher's config path via the environment variable that
 	// GetConfigPath() already reads, so the gateway sub-process uses the same