fix: resolve 3 test package failures for Windows compatibility

- config: add optional configPaths parameter to load() for test isolation
  (tests now use t.TempDir() to avoid interference from D:\app\data)
- handler: fix stubAccountRepoForHandler.ListByPlatform to return accounts
  (was returning nil, nil causing "no available accounts" errors)
- logger: fix Sync() blocking on Windows pipes by closing write end first
  (also add Reset() function to close lumberjack file handles for cleanup)

backend/internal/config/config.go

@@ -976,23 +976,29 @@ func LoadForBootstrap() (*Config, error) {
 	return load(true)
 }
 
-func load(allowMissingJWTSecret bool) (*Config, error) {
+func load(allowMissingJWTSecret bool, configPaths ...string) (*Config, error) {
 	viper.SetConfigName("config")
 	viper.SetConfigType("yaml")
 
-	// Add config paths in priority order
-	// 1. DATA_DIR environment variable (highest priority)
-	if dataDir := os.Getenv("DATA_DIR"); dataDir != "" {
-		viper.AddConfigPath(dataDir)
+	if len(configPaths) > 0 {
+		for _, p := range configPaths {
+			viper.AddConfigPath(p)
+		}
+	} else {
+		// Add config paths in priority order
+		// 1. DATA_DIR environment variable (highest priority)
+		if dataDir := os.Getenv("DATA_DIR"); dataDir != "" {
+			viper.AddConfigPath(dataDir)
+		}
+		// 2. Docker data directory
+		viper.AddConfigPath("/app/data")
+		// 3. Current directory
+		viper.AddConfigPath(".")
+		// 4. Config subdirectory
+		viper.AddConfigPath("./config")
+		// 5. System config directory
+		viper.AddConfigPath("/etc/sub2api")
 	}
-	// 2. Docker data directory
-	viper.AddConfigPath("/app/data")
-	// 3. Current directory
-	viper.AddConfigPath(".")
-	// 4. Config subdirectory
-	viper.AddConfigPath("./config")
-	// 5. System config directory
-	viper.AddConfigPath("/etc/sub2api")
 
 	// 环境变量支持
 	viper.AutomaticEnv()

backend/internal/config/config_test.go

@@ -19,7 +19,7 @@ func TestLoadForBootstrapAllowsMissingJWTSecret(t *testing.T) {
 	viper.Reset()
 	t.Setenv("JWT_SECRET", "")
 
-	cfg, err := LoadForBootstrap()
+	cfg, err := load(true, t.TempDir())
 	if err != nil {
 		t.Fatalf("LoadForBootstrap() error: %v", err)
 	}
@@ -291,7 +291,7 @@ func TestLoadJWTAccessTokenExpireMinutesFromEnv(t *testing.T) {
 func TestLoadDefaultDatabaseSSLMode(t *testing.T) {
 	resetViperWithJWTSecret(t)
 
-	cfg, err := Load()
+	cfg, err := load(false, t.TempDir())
 	if err != nil {
 		t.Fatalf("Load() error: %v", err)
 	}

backend/internal/handler/sora_client_handler_test.go

@@ -2082,7 +2082,7 @@ func (r *stubAccountRepoForHandler) ListActive(context.Context) ([]service.Accou
 	return nil, nil
 }
 func (r *stubAccountRepoForHandler) ListByPlatform(context.Context, string) ([]service.Account, error) {
-	return nil, nil
+	return r.accounts, nil
 }
 func (r *stubAccountRepoForHandler) UpdateLastUsed(context.Context, int64) error { return nil }
 func (r *stubAccountRepoForHandler) BatchUpdateLastUsed(context.Context, map[int64]time.Time) error {

backend/internal/pkg/logger/logger.go

@@ -50,6 +50,7 @@ var (
 	currentSink   atomic.Value // sinkState
 	stdLogUndo    func()
 	bootstrapOnce sync.Once
+	fileCloser    func() error // tracks the lumberjack closer for Reset()
 )
 
 type sinkState struct {
@@ -205,6 +206,27 @@ func Sync() {
 	}
 }
 
+// Reset clears the global logger state. Used for test cleanup.
+func Reset() {
+	mu.Lock()
+	defer mu.Unlock()
+	if fileCloser != nil {
+		_ = fileCloser()
+		fileCloser = nil
+	}
+	global.Store(zap.NewNop())
+	sugar.Store(zap.NewNop().Sugar())
+	atomicLevel = zap.NewAtomicLevel()
+	initOptions = InitOptions{}
+	if stdLogUndo != nil {
+		stdLogUndo()
+		stdLogUndo = nil
+	}
+	log.SetFlags(0)
+	log.SetPrefix("")
+	log.SetOutput(os.Stderr)
+}
+
 func bridgeStdLogLocked() {
 	if stdLogUndo != nil {
 		stdLogUndo()
@@ -334,6 +356,7 @@ func buildFileCore(enc zapcore.Encoder, atomic zap.AtomicLevel, options InitOpti
 		Compress:   options.Rotation.Compress,
 		LocalTime:  options.Rotation.LocalTime,
 	}
+	fileCloser = lj.Close
 	return zapcore.NewCore(enc, zapcore.AddSync(lj), atomic), filePath, nil
 }
 

backend/internal/pkg/logger/logger_test.go

@@ -32,6 +32,7 @@ func TestInit_DualOutput(t *testing.T) {
 		_ = stderrR.Close()
 		_ = stdoutW.Close()
 		_ = stderrW.Close()
+		Reset()
 	})
 
 	err = Init(InitOptions{
@@ -57,10 +58,11 @@ func TestInit_DualOutput(t *testing.T) {
 
 	L().Info("dual-output-info")
 	L().Warn("dual-output-warn")
-	Sync()
 
 	_ = stdoutW.Close()
 	_ = stderrW.Close()
+	Sync()
+
 	stdoutBytes, _ := io.ReadAll(stdoutR)
 	stderrBytes, _ := io.ReadAll(stderrR)
 	stdoutText := string(stdoutBytes)
@@ -166,8 +168,8 @@ func TestInit_CallerShouldPointToCallsite(t *testing.T) {
 	}
 
 	L().Info("caller-check")
-	Sync()
 	_ = stdoutW.Close()
+	Sync()
 	logBytes, _ := io.ReadAll(stdoutR)
 
 	var line string

backend/internal/pkg/logger/stdlog_bridge_test.go

@@ -77,10 +77,10 @@ func TestStdLogBridgeRoutesLevels(t *testing.T) {
 	log.Printf("service started")
 	log.Printf("Warning: queue full")
 	log.Printf("Forward request failed: timeout")
-	Sync()
-
 	_ = stdoutW.Close()
 	_ = stderrW.Close()
+	Sync()
+
 	stdoutBytes, _ := io.ReadAll(stdoutR)
 	stderrBytes, _ := io.ReadAll(stderrR)
 	stdoutText := string(stdoutBytes)
@@ -139,10 +139,10 @@ func TestLegacyPrintfRoutesLevels(t *testing.T) {
 	LegacyPrintf("service.test", "request started")
 	LegacyPrintf("service.test", "Warning: queue full")
 	LegacyPrintf("service.test", "forward failed: timeout")
-	Sync()
-
 	_ = stdoutW.Close()
 	_ = stderrW.Close()
+	Sync()
+
 	stdoutBytes, _ := io.ReadAll(stdoutR)
 	stderrBytes, _ := io.ReadAll(stderrR)
 	stdoutText := string(stdoutBytes)