chore(config): remove unused redis and s3 client constructors

Remove `NewRedis` and `NewS3` factory functions from the config package
to eliminate unused initialization logic and reduce dependency bloat.

internal/config/redis.go

@@ -1,10 +1,7 @@
 package config
 
 import (
-	"context"
 	"fmt"
-
-	"github.com/redis/go-redis/v9"
 )
 
 // RedisConfig Redis 配置
@@ -62,19 +59,3 @@ type MiniredisConfig struct {
 	Port int    `mapstructure:"port"`
 }
 
-// NewRedis 创建 Redis 客户端（真实 Redis）
-func NewRedis(cfg *RedisConfig) (*redis.Client, error) {
-	client := redis.NewClient(&redis.Options{
-		Addr:     cfg.Redis.Addr(),
-		Password: cfg.Redis.Password,
-		DB:       cfg.Redis.DB,
-		PoolSize: cfg.PoolSize,
-	})
-
-	ctx := context.Background()
-	if err := client.Ping(ctx).Err(); err != nil {
-		return nil, fmt.Errorf("failed to connect to redis: %w", err)
-	}
-
-	return client, nil
-}