fix: resolve all golangci-lint issues

- Rename strat->strategy throughout (misspell)
- Pre-allocate slices in tray.go, pac.go (prealloc)
- Fix unchecked Write/Run calls (errcheck)
- Remove unused mu field, errSOCKS5* vars (unused)
- Fix deprecated filepath.HasPrefix->strings.HasPrefix
- Remove impossible nil check in test

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: foursecondfivefour

internal/__pycache__/fix_translations.cpython-314.pyc

@@ -0,0 +1,42 @@
+{
+  "LangFR": {
+    "Возможности YouTube": "Fonctionnalités YouTube",
+    "TUN режим блокирует весь исходящий трафик кроме Conduit. Включайте только если понимаете риск.": "Le mode TUN bloque tout le trafic sortant sauf Conduit. Activez-le seulement si vous comprenez le risque.",
+    "Доступна версия %s. Установить сейчас?": "Version %s disponible. Installer maintenant ?",
+    "Загрузка %d%%": "Téléchargement %d%%",
+    "Задержка: %dмс, Скачивание: %.1f Мбит/с": "Latence : %dms, Téléchargement : %.1f Mbit/s",
+    "Локальный прокси Conduit без аутентификации будет использоваться другими приложениями на этом компьютере в пределах allowlist. Включайте только если понимаете риск.": "Le proxy local Conduit sans authentification sera utilisé par d'autres applications sur cet ordinateur dans la limite de l'allowlist. Activez-le seulement si vous comprenez le risque.",
+    "Соединение OK": "Connexion OK",
+    "Порты": "Ports",
+    "работает": "en cours",
+    "Обновления": "Mises à jour",
+    "Порт SOCKS5: %d": "Port SOCKS5 : %d",
+    "Блокировать системный DNS": "Bloquer le DNS système",
+    "Прокси %s (:%d) | %s | %s DoH | %s": "Proxy %s (:%d) | %s | %s DoH | %s",
+    "Напомнить позже": "Rappeler plus tard",
+    "Требуется перезапуск": "Redémarrage requis",
+    "Заблокировано доменов: %d": "Domaines bloqués : %d",
+    "Авто-подключение": "Connexion automatique",
+    "Экспорт настроек": "Exporter les paramètres",
+    "Импорт настроек": "Importer les paramètres",
+    "Только YouTube": "YouTube uniquement",
+    "Выбран %s (%dмс)": "%s sélectionné (%dms)",
+    "Соединение не удалось: %s": "Connexion échouée : %s",
+    "Доступно v%s": "Disponible v%s",
+    "Проверить сейчас": "Vérifier maintenant",
+    "Настройка портов": "Configurer les ports",
+    "Стратегия DPI": "Stratégie DPI",
+    "Сбросить custom": "Réinitialiser custom",
+    "Системный прокси": "Proxy système",
+    "Обновление готово": "Mise à jour prête",
+    "Выйти из PiP": "Quitter le PiP",
+    "Перезагрузить YouTube": "Recharger YouTube",
+    "Настройки загружены": "Paramètres importés",
+    "Загрузка списка...": "Chargement de la liste...",
+    "Блокировка рекламы (DNS)": "Blocage de pub (DNS)",
+    "Домены": "Domaines",
+    "Сброс DNS кэша": "Vider le cache DNS",
+    "Фоновое аудио": "Audio en arrière-plan",
+    "Статистика": "Statistiques"
+  }
+}

internal/_trans_data.json

@@ -42,7 +42,7 @@ func ApplyPreferences(p Preferences, settings *config.Settings) {
 		settings.WindowHeight = p.WindowHeight
 	}
 
-	if p.DomainStrategies != nil && len(p.DomainStrategies) > 0 {
+	if len(p.DomainStrategies) > 0 {
 		settings.DomainStrategies = make(map[string]string, len(p.DomainStrategies))
 		for k, v := range p.DomainStrategies {
 			settings.DomainStrategies[k] = v

internal/app/settings.go

@@ -126,7 +126,7 @@ func (ui *trayUI) rebuildMenu() {
 	ui.statusItem.SetEnabled(false)
 
 	// DPI strategies
-	var strategyItems []*application.MenuItem
+	strategyItems := make([]*application.MenuItem, 0, len(ui.deps.control.ListStrategies()))
 	for _, strategy := range ui.deps.control.ListStrategies() {
 		s := strategy
 		item := application.NewMenuItemRadio(strategyMenuLabel(lang, s), ui.deps.control.Settings().Strategy == s)
@@ -140,7 +140,7 @@ func (ui *trayUI) rebuildMenu() {
 	strategyMenu := menuFromItems(strategyItems)
 
 	// DNS providers
-	var dnsItems []*application.MenuItem
+	dnsItems := make([]*application.MenuItem, 0, len(ui.deps.control.ListDoHProviders()))
 	for _, provider := range ui.deps.control.ListDoHProviders() {
 		pr := provider
 		item := application.NewMenuItemRadio(provider.ShortLabel(), ui.deps.control.Settings().DoHProvider == pr)
@@ -185,7 +185,7 @@ func (ui *trayUI) rebuildMenu() {
 	dnsMenu := menuFromItems(dnsSubItems)
 
 	// Domains
-	var domainItems []*application.MenuItem
+	domainItems := make([]*application.MenuItem, 0, len(ui.deps.control.ListAllowlistPresets()))
 	for _, preset := range ui.deps.control.ListAllowlistPresets() {
 		pr := preset
 		label := domainPresetLabel(lang, pr)

internal/app/tray.go

@@ -238,7 +238,7 @@ func parseDoHResponse(body []byte) ([]net.IP, time.Duration, error) {
 		return nil, 0, err
 	}
 
-	var ips []net.IP
+	ips := make([]net.IP, 0, len(payload.Answer))
 	var minTTL int
 	for _, answer := range payload.Answer {
 		if answer.Type != 1 && answer.Type != 28 {

internal/dns/doh.go

@@ -312,7 +312,5 @@ func TestAdBlockerNotBlockedWhenNoBlocker(t *testing.T) {
 
 func TestLeakDetectorStructure(t *testing.T) {
 	d := &LeakDetector{}
-	if d == nil {
-		t.Fatal("LeakDetector should not be nil")
-	}
+	_ = d // ensure d is used; it can never be nil after allocation
 }

internal/dns/doh_test.go

@@ -12,14 +12,14 @@ import (
 type AIStrategySelector struct {
 	mu           sync.RWMutex
 	cache        map[string]Strategy
-	defaultStrat Strategy
+	defaultStrategy Strategy
 }
 
 // NewAIStrategySelector creates a new AI strategy selector with a default fallback.
-func NewAIStrategySelector(defaultStrat Strategy) *AIStrategySelector {
+func NewAIStrategySelector(defaultStrategy Strategy) *AIStrategySelector {
 	return &AIStrategySelector{
-		cache:        make(map[string]Strategy),
-		defaultStrat: defaultStrat,
+		cache:           make(map[string]Strategy),
+		defaultStrategy: defaultStrategy,
 	}
 }
 
@@ -28,17 +28,17 @@ func NewAIStrategySelector(defaultStrat Strategy) *AIStrategySelector {
 func (s *AIStrategySelector) GetStrategyForHost(host string) Strategy {
 	s.mu.RLock()
 	defer s.mu.RUnlock()
-	if strat, ok := s.cache[host]; ok {
-		return strat
+	if strategy, ok := s.cache[host]; ok {
+		return strategy
 	}
-	return s.defaultStrat
+	return s.defaultStrategy
 }
 
 // RecordStrategy memorizes a working strategy for a host.
-func (s *AIStrategySelector) RecordStrategy(host string, strat Strategy) {
+func (s *AIStrategySelector) RecordStrategy(host string, strategy Strategy) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
-	s.cache[host] = strat
+	s.cache[host] = strategy
 }
 
 // ProbeHost tries all strategies against a host and returns the first working one.
@@ -47,18 +47,18 @@ func (s *AIStrategySelector) ProbeHost(ctx context.Context, host string, port in
 	strategies := AllStrategies()
 	address := net.JoinHostPort(host, fmt.Sprintf("%d", port))
 
-	for _, strat := range strategies {
-		if strat == StrategyNone {
+	for _, strategyCandidate := range strategies {
+		if strategyCandidate == StrategyNone {
 			continue // skip "none" — prefer fragmentation
 		}
 		conn, err := dial(ctx, "tcp", address)
 		if err != nil {
 			continue
 		}
 		conn.Close()
-		s.RecordStrategy(host, strat)
-		return strat, nil
+		s.RecordStrategy(host, strategyCandidate)
+		return strategyCandidate, nil
 	}
 
-	return s.defaultStrat, fmt.Errorf("no working strategy found for %s", host)
+	return s.defaultStrategy, fmt.Errorf("no working strategy found for %s", host)
 }

internal/dpi/ai.go

@@ -130,16 +130,16 @@ func TestAIStrategySelectorProbeHost(t *testing.T) {
 		return client, nil
 	}
 
-	strat, err := selector.ProbeHost(context.Background(), "test.com", 443, dial)
-	if err != nil || strat.Valid() == false {
-		t.Fatalf("ProbeHost failed: err=%v strat=%s", err, strat)
+	strategy, err := selector.ProbeHost(context.Background(), "test.com", 443, dial)
+	if err != nil || strategy.Valid() == false {
+		t.Fatalf("ProbeHost failed: err=%v strategy=%s", err, strategy)
 	}
-	if strat == StrategyNone {
+	if strategy == StrategyNone {
 		t.Fatal("probe should not return StrategyNone")
 	}
 	cached := selector.GetStrategyForHost("test.com")
-	if cached != strat {
-		t.Fatalf("cached = %s, want %s", cached, strat)
+	if cached != strategy {
+		t.Fatalf("cached = %s, want %s", cached, strategy)
 	}
 }
 
@@ -150,12 +150,12 @@ func TestAIStrategySelectorProbeAllFail(t *testing.T) {
 		return nil, net.ErrClosed
 	}
 
-	strat, err := selector.ProbeHost(context.Background(), "bad.com", 443, dial)
+	strategy, err := selector.ProbeHost(context.Background(), "bad.com", 443, dial)
 	if err == nil {
 		t.Fatal("expected error when all probes fail")
 	}
-	if strat != StrategyTCPSegmentation8 {
-		t.Fatalf("fallback strategy = %s, want %s", strat, StrategyTCPSegmentation8)
+	if strategy != StrategyTCPSegmentation8 {
+		t.Fatalf("fallback strategy = %s, want %s", strategy, StrategyTCPSegmentation8)
 	}
 }
 

internal/dpi/fragment_test.go

@@ -56,6 +56,7 @@ func DialChain(ctx context.Context, upstream *UpstreamProxy, targetNetwork, targ
 		conn.Close()
 		return nil, err
 	}
+	defer resp.Body.Close()
 	if resp.StatusCode != http.StatusOK {
 		conn.Close()
 		return nil, fmt.Errorf("upstream proxy returned %d", resp.StatusCode)

internal/proxy/chain.go

@@ -8,7 +8,7 @@ import (
 
 // GeneratePAC creates a PAC file that routes allowed domains through the proxy.
 func GeneratePAC(proxyHost string, proxyPort int, domains []string) string {
-	var conditions []string
+	conditions := make([]string, 0, len(domains)*2)
 	for _, d := range domains {
 		d = strings.TrimPrefix(d, ".")
 		conditions = append(conditions, fmt.Sprintf(`dnsDomainIs(host, "%s")`, d))