优化

internal/config/defaults.go

@@ -43,6 +43,7 @@ func setDefaults(v *viper.Viper) {
 	v.SetDefault("logging.max_backups", 10)
 
 	v.SetDefault("cache.cache_dir", "./cache")
+	v.SetDefault("cache.images_max_size_mb", 500)
 	v.SetDefault("cache.cleanup_interval_min", 60)
 	v.SetDefault("cache.redis_url", "")
 	v.SetDefault("cache.redis_prefix", "mmtl")

internal/config/normalize.go

@@ -44,6 +44,9 @@ func (c *Config) normalize() error {
 	if c.Cache.CacheDir == "" {
 		c.Cache.CacheDir = filepath.Join(c.App.DataDir, "cache")
 	}
+	if c.Cache.ImagesMaxSizeMB < 0 {
+		c.Cache.ImagesMaxSizeMB = 0
+	}
 	if c.Cache.RedisPrefix == "" {
 		c.Cache.RedisPrefix = "mmtl"
 	}

internal/config/types.go

@@ -116,6 +116,7 @@ type LoggingConfig struct {
 // CacheConfig 控制磁盘转码/刮削缓存。
 type CacheConfig struct {
 	CacheDir           string `mapstructure:"cache_dir"`
+	ImagesMaxSizeMB    int    `mapstructure:"images_max_size_mb"`
 	MaxDiskUsageMB     int    `mapstructure:"max_disk_usage_mb"`
 	TTLHours           int    `mapstructure:"ttl_hours"`
 	AutoCleanup        bool   `mapstructure:"auto_cleanup"`