Merge branch 'main' into test

# Conflicts:
#	backend/cmd/server/VERSION
#	backend/ent/migrate/schema.go
#	backend/ent/mutation.go
#	backend/ent/runtime/runtime.go
#	backend/ent/usagelog.go
#	backend/ent/usagelog/usagelog.go
#	backend/ent/usagelog/where.go
#	backend/ent/usagelog_create.go
#	backend/ent/usagelog_update.go
#	backend/internal/repository/usage_log_repo.go
#	backend/internal/server/api_contract_test.go
#	backend/internal/server/middleware/cors.go
#	backend/internal/service/gateway_service.go

backend/internal/service/usage_log.go

@@ -46,6 +46,9 @@ type UsageLog struct {
 	UserAgent    *string
 	IPAddress    *string
 
+	// Cache TTL Override 标记（管理员强制替换了缓存 TTL 计费）
+	CacheTTLOverridden bool
+
 	// 图片生成字段
 	ImageCount int
 	ImageSize  *string