feat: 新增启动参数设置页面，区分 desktop 可编辑与 server 只读

backend/internal/config/config.go

@@ -36,7 +36,7 @@ type DatabaseConfig struct {
 	Driver          string        `yaml:"driver" mapstructure:"driver" validate:"required,oneof=sqlite mysql"`
 	Path            string        `yaml:"path" mapstructure:"path" validate:"required_if=Driver sqlite"`
 	Host            string        `yaml:"host" mapstructure:"host" validate:"required_if=Driver mysql"`
-	Port            int           `yaml:"port" mapstructure:"port" validate:"required_if=Driver mysql,min=1,max=65535"`
+	Port            int           `yaml:"port" mapstructure:"port" validate:"required_if=Driver mysql,omitempty,min=1,max=65535"`
 	User            string        `yaml:"user" mapstructure:"user" validate:"required_if=Driver mysql"`
 	Password        string        `yaml:"password" mapstructure:"password"`
 	DBName          string        `yaml:"dbname" mapstructure:"dbname" validate:"required_if=Driver mysql"`
@@ -233,7 +233,10 @@ func setupConfigFile(v *viper.Viper, configPath string) error {
 	return nil
 }
 
-// loadOptions 控制配置加载器行为
+type ConfigMetadata struct {
+	ConfigPath string
+}
+
 type loadOptions struct {
 	configPathOverride string
 	useCLI             bool
@@ -270,15 +273,19 @@ func resolveConfigPath(v *viper.Viper, opts loadOptions) (string, error) {
 	return configPath, nil
 }
 
-// loadConfig 共享配置加载逻辑，通过 loadOptions 控制是否启用 CLI、环境变量和 --config 覆盖
 func loadConfig(opts loadOptions) (*Config, error) {
+	cfg, _, err := loadConfigWithMetadata(opts)
+	return cfg, err
+}
+
+func loadConfigWithMetadata(opts loadOptions) (*Config, ConfigMetadata, error) {
 	v := viper.New()
 
 	setupDefaults(v)
 
 	configPath, err := resolveConfigPath(v, opts)
 	if err != nil {
-		return nil, err
+		return nil, ConfigMetadata{}, err
 	}
 
 	if opts.useEnv {
@@ -286,7 +293,7 @@ func loadConfig(opts loadOptions) (*Config, error) {
 	}
 
 	if err := setupConfigFile(v, configPath); err != nil {
-		return nil, err
+		return nil, ConfigMetadata{}, err
 	}
 
 	cfg := &Config{}
@@ -294,23 +301,28 @@ func loadConfig(opts loadOptions) (*Config, error) {
 		mapstructure.StringToTimeDurationHookFunc(),
 		mapstructure.StringToSliceHookFunc(","),
 	))); err != nil {
-		return nil, appErrors.Wrap(appErrors.ErrInternal, err)
+		return nil, ConfigMetadata{}, appErrors.Wrap(appErrors.ErrInternal, err)
 	}
 
 	if err := cfg.Validate(); err != nil {
-		return nil, err
+		return nil, ConfigMetadata{}, err
 	}
 
-	return cfg, nil
+	return cfg, ConfigMetadata{ConfigPath: configPath}, nil
 }
 
 // LoadServerConfig 为 server 入口加载配置，支持 CLI 参数、环境变量和 --config
 func LoadServerConfig() (*Config, error) {
+	cfg, _, err := LoadServerConfigWithMetadata()
+	return cfg, err
+}
+
+func LoadServerConfigWithMetadata() (*Config, ConfigMetadata, error) {
 	configPath, err := GetConfigPath()
 	if err != nil {
-		return nil, appErrors.Wrap(appErrors.ErrInternal, err)
+		return nil, ConfigMetadata{}, appErrors.Wrap(appErrors.ErrInternal, err)
 	}
-	return loadConfig(loadOptions{
+	return loadConfigWithMetadata(loadOptions{
 		configPathOverride: configPath,
 		useCLI:             true,
 		useEnv:             true,
@@ -320,11 +332,16 @@ func LoadServerConfig() (*Config, error) {
 
 // LoadDesktopConfig 为 desktop 入口加载配置，固定使用默认配置文件，不支持 CLI、环境变量和 --config
 func LoadDesktopConfig() (*Config, error) {
+	cfg, _, err := LoadDesktopConfigWithMetadata()
+	return cfg, err
+}
+
+func LoadDesktopConfigWithMetadata() (*Config, ConfigMetadata, error) {
 	configPath, err := GetConfigPath()
 	if err != nil {
-		return nil, appErrors.Wrap(appErrors.ErrInternal, err)
+		return nil, ConfigMetadata{}, appErrors.Wrap(appErrors.ErrInternal, err)
 	}
-	return loadConfig(loadOptions{
+	return loadConfigWithMetadata(loadOptions{
 		configPathOverride: configPath,
 		useCLI:             false,
 		useEnv:             false,
@@ -365,13 +382,15 @@ func SaveConfig(cfg *Config) error {
 	if err != nil {
 		return appErrors.Wrap(appErrors.ErrInternal, err)
 	}
+	return SaveConfigToPath(cfg, configPath)
+}
 
+func SaveConfigToPath(cfg *Config, configPath string) error {
 	data, err := yaml.Marshal(cfg)
 	if err != nil {
 		return appErrors.Wrap(appErrors.ErrInternal, err)
 	}
 
-	// Ensure directory exists
 	dir := filepath.Dir(configPath)
 	if err := os.MkdirAll(dir, 0o755); err != nil {
 		return appErrors.Wrap(appErrors.ErrInternal, err)

backend/internal/config/config_metadata_test.go

@@ -0,0 +1,94 @@
+package config
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"gopkg.in/yaml.v3"
+)
+
+func TestLoadDesktopConfigAtPath_WithMetadata(t *testing.T) {
+	dir := t.TempDir()
+	configPath := filepath.Join(dir, "config.yaml")
+
+	cfg := DefaultConfig()
+	cfg.Server.Port = 8888
+	data, err := yaml.Marshal(cfg)
+	require.NoError(t, err)
+	require.NoError(t, os.WriteFile(configPath, data, 0o600))
+
+	loaded, meta, err := loadConfigWithMetadata(loadOptions{
+		configPathOverride: configPath,
+		useCLI:             false,
+		useEnv:             false,
+		useConfigFlag:      false,
+	})
+	require.NoError(t, err)
+	assert.Equal(t, 8888, loaded.Server.Port)
+	assert.Equal(t, configPath, meta.ConfigPath)
+}
+
+func TestSaveConfigToPath(t *testing.T) {
+	dir := t.TempDir()
+	configPath := filepath.Join(dir, "sub", "config.yaml")
+
+	cfg := DefaultConfig()
+	cfg.Server.Port = 7777
+
+	err := SaveConfigToPath(cfg, configPath)
+	require.NoError(t, err)
+
+	data, err := os.ReadFile(configPath)
+	require.NoError(t, err)
+	assert.Contains(t, string(data), "7777")
+}
+
+func TestSaveConfigToPath_InvalidDir(t *testing.T) {
+	cfg := DefaultConfig()
+	err := SaveConfigToPath(cfg, "/dev/null/impossible/config.yaml")
+	assert.Error(t, err)
+}
+
+func TestDurationConversion(t *testing.T) {
+	cfg := DefaultConfig()
+	dto := configToDTO(cfg)
+
+	parsed, err := time.ParseDuration(dto.Server.ReadTimeout)
+	require.NoError(t, err)
+	assert.Equal(t, cfg.Server.ReadTimeout, parsed)
+
+	parsed, err = time.ParseDuration(dto.Database.ConnMaxLifetime)
+	require.NoError(t, err)
+	assert.Equal(t, cfg.Database.ConnMaxLifetime, parsed)
+}
+
+func configToDTO(c *Config) struct {
+	Server struct {
+		Port         int    `json:"port"`
+		ReadTimeout  string `json:"read_timeout"`
+		WriteTimeout string `json:"write_timeout"`
+	}
+	Database struct {
+		ConnMaxLifetime string `json:"conn_max_lifetime"`
+	}
+} {
+	var result struct {
+		Server struct {
+			Port         int    `json:"port"`
+			ReadTimeout  string `json:"read_timeout"`
+			WriteTimeout string `json:"write_timeout"`
+		}
+		Database struct {
+			ConnMaxLifetime string `json:"conn_max_lifetime"`
+		}
+	}
+	result.Server.Port = c.Server.Port
+	result.Server.ReadTimeout = c.Server.ReadTimeout.String()
+	result.Server.WriteTimeout = c.Server.WriteTimeout.String()
+	result.Database.ConnMaxLifetime = c.Database.ConnMaxLifetime.String()
+	return result
+}