feat(backend): Go 服务骨架（配置、日志、数据库、中间件、Wire）

- config: Viper YAML 配置 + 环境变量覆盖
- logs: zap 结构化日志 + trace_id 链路追踪 + 敏感信息脱敏
- db: PostgreSQL (GORM) + Redis (go-redis) 连接管理
- middleware: Trace/Logger/CORS/Recovery 四层中间件
- provider: Wire 编译时依赖注入
- main.go: 优雅启动/关闭 HTTP 服务

Made-with: Cursor

backend/go-service/app/provider/provider.go

@@ -0,0 +1,46 @@
+// Package provider 提供全局依赖注入配置
+// 使用 Wire 编译时依赖注入，集中管理所有模块的 Provider Set
+package provider
+
+import (
+	"github.com/echochat/backend/config"
+	"github.com/echochat/backend/pkg/db"
+	"github.com/google/wire"
+	"github.com/redis/go-redis/v9"
+	"gorm.io/gorm"
+)
+
+// App 应用根容器，持有所有基础设施组件
+type App struct {
+	Config *config.Config
+	DB     *gorm.DB
+	Redis  *redis.Client
+}
+
+// NewApp 创建应用实例
+func NewApp(cfg *config.Config, gormDB *gorm.DB, redisClient *redis.Client) *App {
+	return &App{
+		Config: cfg,
+		DB:     gormDB,
+		Redis:  redisClient,
+	}
+}
+
+// provideDBConfig 从全局 Config 中提取 DatabaseConfig
+func provideDBConfig(cfg *config.Config) *config.DatabaseConfig {
+	return &cfg.Database
+}
+
+// provideRedisConfig 从全局 Config 中提取 RedisConfig
+func provideRedisConfig(cfg *config.Config) *config.RedisConfig {
+	return &cfg.Redis
+}
+
+// InfraSet 基础设施层 Provider Set
+var InfraSet = wire.NewSet(
+	provideDBConfig,
+	provideRedisConfig,
+	db.NewPostgres,
+	db.NewRedis,
+	NewApp,
+)

backend/go-service/app/provider/wire.go

@@ -0,0 +1,17 @@
+//go:build wireinject
+
+// Package provider 提供 Wire 依赖注入入口
+package provider
+
+import (
+	"github.com/echochat/backend/config"
+	"github.com/google/wire"
+)
+
+// InitializeApp 初始化整个应用（Wire 自动生成实现）
+func InitializeApp(cfg *config.Config) (*App, error) {
+	wire.Build(
+		InfraSet,
+	)
+	return nil, nil
+}

backend/go-service/app/provider/wire_gen.go

@@ -0,0 +1,30 @@
+// Code generated by Wire. DO NOT EDIT.
+
+//go:generate go run -mod=mod github.com/google/wire/cmd/wire
+//go:build !wireinject
+// +build !wireinject
+
+package provider
+
+import (
+	"github.com/echochat/backend/config"
+	"github.com/echochat/backend/pkg/db"
+)
+
+// Injectors from wire.go:
+
+// InitializeApp 初始化整个应用（Wire 自动生成实现）
+func InitializeApp(cfg *config.Config) (*App, error) {
+	databaseConfig := provideDBConfig(cfg)
+	gormDB, err := db.NewPostgres(databaseConfig)
+	if err != nil {
+		return nil, err
+	}
+	redisConfig := provideRedisConfig(cfg)
+	client, err := db.NewRedis(redisConfig)
+	if err != nil {
+		return nil, err
+	}
+	app := NewApp(cfg, gormDB, client)
+	return app, nil
+}