feat(sora): 新增 Sora 平台支持并修复高危安全和性能问题

新增功能：
- 新增 Sora 账号管理和 OAuth 认证
- 新增 Sora 视频/图片生成 API 网关
- 新增 Sora 任务调度和缓存机制
- 新增 Sora 使用统计和计费支持
- 前端增加 Sora 平台配置界面

安全修复（代码审核）：
- [SEC-001] 限制媒体下载响应体大小（图片 20MB、视频 200MB），防止 DoS 攻击
- [SEC-002] 限制 SDK API 响应大小（1MB），防止内存耗尽
- [SEC-003] 修复 SSRF 风险，添加 URL 验证并强制使用代理配置

BUG 修复（代码审核）：
- [BUG-001] 修复 for 循环内 defer 累积导致的资源泄漏
- [BUG-002] 修复图片并发槽位获取失败时已持有锁未释放的永久泄漏

性能优化（代码审核）：
- [PERF-001] 添加 Sentinel Token 缓存（3 分钟有效期），减少 PoW 计算开销

技术细节：
- 使用 io.LimitReader 限制所有外部输入的大小
- 添加 urlvalidator 验证防止 SSRF 攻击
- 使用 sync.Map 实现线程安全的包级缓存
- 优化并发槽位管理，添加 releaseAll 模式防止泄漏

影响范围：
- 后端：新增 Sora 相关数据模型、服务、网关和管理接口
- 前端：新增 Sora 平台配置、账号管理和监控界面
- 配置：新增 Sora 相关配置项和环境变量

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

backend/ent/soracachefile/soracachefile.go

@@ -0,0 +1,124 @@
+// Code generated by ent, DO NOT EDIT.
+
+package soracachefile
+
+import (
+	"time"
+
+	"entgo.io/ent/dialect/sql"
+)
+
+const (
+	// Label holds the string label denoting the soracachefile type in the database.
+	Label = "sora_cache_file"
+	// FieldID holds the string denoting the id field in the database.
+	FieldID = "id"
+	// FieldTaskID holds the string denoting the task_id field in the database.
+	FieldTaskID = "task_id"
+	// FieldAccountID holds the string denoting the account_id field in the database.
+	FieldAccountID = "account_id"
+	// FieldUserID holds the string denoting the user_id field in the database.
+	FieldUserID = "user_id"
+	// FieldMediaType holds the string denoting the media_type field in the database.
+	FieldMediaType = "media_type"
+	// FieldOriginalURL holds the string denoting the original_url field in the database.
+	FieldOriginalURL = "original_url"
+	// FieldCachePath holds the string denoting the cache_path field in the database.
+	FieldCachePath = "cache_path"
+	// FieldCacheURL holds the string denoting the cache_url field in the database.
+	FieldCacheURL = "cache_url"
+	// FieldSizeBytes holds the string denoting the size_bytes field in the database.
+	FieldSizeBytes = "size_bytes"
+	// FieldCreatedAt holds the string denoting the created_at field in the database.
+	FieldCreatedAt = "created_at"
+	// Table holds the table name of the soracachefile in the database.
+	Table = "sora_cache_files"
+)
+
+// Columns holds all SQL columns for soracachefile fields.
+var Columns = []string{
+	FieldID,
+	FieldTaskID,
+	FieldAccountID,
+	FieldUserID,
+	FieldMediaType,
+	FieldOriginalURL,
+	FieldCachePath,
+	FieldCacheURL,
+	FieldSizeBytes,
+	FieldCreatedAt,
+}
+
+// ValidColumn reports if the column name is valid (part of the table columns).
+func ValidColumn(column string) bool {
+	for i := range Columns {
+		if column == Columns[i] {
+			return true
+		}
+	}
+	return false
+}
+
+var (
+	// TaskIDValidator is a validator for the "task_id" field. It is called by the builders before save.
+	TaskIDValidator func(string) error
+	// MediaTypeValidator is a validator for the "media_type" field. It is called by the builders before save.
+	MediaTypeValidator func(string) error
+	// DefaultSizeBytes holds the default value on creation for the "size_bytes" field.
+	DefaultSizeBytes int64
+	// DefaultCreatedAt holds the default value on creation for the "created_at" field.
+	DefaultCreatedAt func() time.Time
+)
+
+// OrderOption defines the ordering options for the SoraCacheFile queries.
+type OrderOption func(*sql.Selector)
+
+// ByID orders the results by the id field.
+func ByID(opts ...sql.OrderTermOption) OrderOption {
+	return sql.OrderByField(FieldID, opts...).ToFunc()
+}
+
+// ByTaskID orders the results by the task_id field.
+func ByTaskID(opts ...sql.OrderTermOption) OrderOption {
+	return sql.OrderByField(FieldTaskID, opts...).ToFunc()
+}
+
+// ByAccountID orders the results by the account_id field.
+func ByAccountID(opts ...sql.OrderTermOption) OrderOption {
+	return sql.OrderByField(FieldAccountID, opts...).ToFunc()
+}
+
+// ByUserID orders the results by the user_id field.
+func ByUserID(opts ...sql.OrderTermOption) OrderOption {
+	return sql.OrderByField(FieldUserID, opts...).ToFunc()
+}
+
+// ByMediaType orders the results by the media_type field.
+func ByMediaType(opts ...sql.OrderTermOption) OrderOption {
+	return sql.OrderByField(FieldMediaType, opts...).ToFunc()
+}
+
+// ByOriginalURL orders the results by the original_url field.
+func ByOriginalURL(opts ...sql.OrderTermOption) OrderOption {
+	return sql.OrderByField(FieldOriginalURL, opts...).ToFunc()
+}
+
+// ByCachePath orders the results by the cache_path field.
+func ByCachePath(opts ...sql.OrderTermOption) OrderOption {
+	return sql.OrderByField(FieldCachePath, opts...).ToFunc()
+}
+
+// ByCacheURL orders the results by the cache_url field.
+func ByCacheURL(opts ...sql.OrderTermOption) OrderOption {
+	return sql.OrderByField(FieldCacheURL, opts...).ToFunc()
+}
+
+// BySizeBytes orders the results by the size_bytes field.
+func BySizeBytes(opts ...sql.OrderTermOption) OrderOption {
+	return sql.OrderByField(FieldSizeBytes, opts...).ToFunc()
+}
+
+// ByCreatedAt orders the results by the created_at field.
+func ByCreatedAt(opts ...sql.OrderTermOption) OrderOption {
+	return sql.OrderByField(FieldCreatedAt, opts...).ToFunc()
+}