feat(Sora): 完成Sora网关接入与媒体能力

新增 Sora 网关路由、账号调度与同步服务\n补充媒体代理与签名 URL、模型列表动态拉取\n完善计费配置、前端支持与相关测试

backend/internal/handler/gateway_handler.go

@@ -29,6 +29,7 @@ type GatewayHandler struct {
 	geminiCompatService       *service.GeminiMessagesCompatService
 	antigravityGatewayService *service.AntigravityGatewayService
 	userService               *service.UserService
+	sora2apiService           *service.Sora2APIService
 	billingCacheService       *service.BillingCacheService
 	concurrencyHelper         *ConcurrencyHelper
 	maxAccountSwitches        int
@@ -41,6 +42,7 @@ func NewGatewayHandler(
 	geminiCompatService *service.GeminiMessagesCompatService,
 	antigravityGatewayService *service.AntigravityGatewayService,
 	userService *service.UserService,
+	sora2apiService *service.Sora2APIService,
 	concurrencyService *service.ConcurrencyService,
 	billingCacheService *service.BillingCacheService,
 	cfg *config.Config,
@@ -62,6 +64,7 @@ func NewGatewayHandler(
 		geminiCompatService:       geminiCompatService,
 		antigravityGatewayService: antigravityGatewayService,
 		userService:               userService,
+		sora2apiService:           sora2apiService,
 		billingCacheService:       billingCacheService,
 		concurrencyHelper:         NewConcurrencyHelper(concurrencyService, SSEPingFormatClaude, pingInterval),
 		maxAccountSwitches:        maxAccountSwitches,
@@ -478,6 +481,26 @@ func (h *GatewayHandler) Models(c *gin.Context) {
 		groupID = &apiKey.Group.ID
 		platform = apiKey.Group.Platform
 	}
+	if forcedPlatform, ok := middleware2.GetForcePlatformFromContext(c); ok && strings.TrimSpace(forcedPlatform) != "" {
+		platform = forcedPlatform
+	}
+
+	if platform == service.PlatformSora {
+		if h.sora2apiService == nil || !h.sora2apiService.Enabled() {
+			h.errorResponse(c, http.StatusServiceUnavailable, "api_error", "sora2api not configured")
+			return
+		}
+		models, err := h.sora2apiService.ListModels(c.Request.Context())
+		if err != nil {
+			h.errorResponse(c, http.StatusServiceUnavailable, "api_error", "Failed to fetch Sora models")
+			return
+		}
+		c.JSON(http.StatusOK, gin.H{
+			"object": "list",
+			"data":   models,
+		})
+		return
+	}
 
 	// Get available models from account configurations (without platform filter)
 	availableModels := h.gatewayService.GetAvailableModels(c.Request.Context(), groupID, "")