feat(watcher): add macOS autostart support via launchd

internal/watcher/autostart.go

@@ -0,0 +1,37 @@
+package watcher
+
+import (
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+)
+
+func EnsureAutostart() error {
+	if isAutostartInstalled() || isTemporaryExecutable() {
+		return nil
+	}
+
+	return installAutostart()
+}
+
+func isAutostartInstalled() bool {
+	switch runtime.GOOS {
+	case "darwin":
+		path := filepath.Join(os.Getenv("HOME"), "Library", "LaunchAgents", "com.godeez.watch.plist")
+		_, err := os.Stat(path)
+
+		return err == nil
+	default:
+		return false
+	}
+}
+
+func isTemporaryExecutable() bool {
+	exe, err := os.Executable()
+	if err != nil {
+		return true
+	}
+
+	return strings.Contains(exe, "go-build")
+}