feat(api): 模型接入 - 统一出网 User-Agent 并支持添加时测试模型

Fixes #39

backend/internal/handler/auth.go

@@ -694,6 +694,7 @@ func proxySystemRequest(c *gin.Context, svc *service.Service, user *model.User,
 	if accept := c.GetHeader("Accept"); accept != "" {
 		upstreamReq.Header.Set("Accept", accept)
 	}
+	service.ApplyDefaultOutboundHeaders(upstreamReq)
 	if protocol == model.ChannelInterfaceGeminiVeo {
 		upstreamReq.Header.Set("x-goog-api-key", channel.APIKey)
 	} else {

backend/internal/handler/custom_proxy.go

@@ -97,7 +97,7 @@ func proxyCustomRelayRequest(c *gin.Context, policy service.RuntimeRequestPolicy
 	} else {
 		upstreamReq.Header.Set("Accept", "application/json")
 	}
-	upstreamReq.Header.Set("User-Agent", "InfiniteCanvas/custom-channel-relay")
+	service.ApplyDefaultOutboundHeaders(upstreamReq)
 	if apiFormat == "gemini" {
 		upstreamReq.Header.Set("x-goog-api-key", apiKey)
 	} else {

backend/internal/handler/custom_proxy_test.go

@@ -22,6 +22,9 @@ func TestCustomRelayForwardsOpenAIRequestWithoutBrowserHeaders(t *testing.T) {
 		if r.Header.Get("Authorization") != "Bearer "+apiKey {
 			t.Errorf("Authorization = %q", r.Header.Get("Authorization"))
 		}
+		if r.Header.Get("User-Agent") != service.DefaultOutboundUserAgent {
+			t.Errorf("User-Agent = %q", r.Header.Get("User-Agent"))
+		}
 		for _, name := range []string{"Cookie", "Origin", "Referer", "X-Canvas-Upstream-URL", "X-Forwarded-For"} {
 			if value := r.Header.Get(name); value != "" {
 				t.Errorf("upstream received %s = %q", name, value)

backend/internal/handler/finance.go

@@ -222,6 +222,28 @@ func RegisterFinanceRoutes(r *gin.RouterGroup, svc *service.Service) {
 		}
 		ok(c, result)
 	})
+	r.POST("/admin/channels/:id/models/test", func(c *gin.Context) {
+		user, err := currentUser(c, svc)
+		if err != nil {
+			failService(c, err)
+			return
+		}
+		if !enforceRateLimit(c, "admin-channel-model-test:"+user.ID+":"+c.Param("id"), 5, time.Minute) {
+			return
+		}
+		c.Request.Body = http.MaxBytesReader(c.Writer, c.Request.Body, 64<<10)
+		var req service.ChannelModelRequest
+		if err := c.ShouldBindJSON(&req); err != nil {
+			fail(c, http.StatusBadRequest, err)
+			return
+		}
+		result, err := svc.TestAdminChannelModel(c.Request.Context(), user, c.Param("id"), req)
+		if err != nil {
+			failService(c, err)
+			return
+		}
+		ok(c, result)
+	})
 	r.POST("/admin/channels/:id/models", func(c *gin.Context) {
 		saveChannelModel(c, svc, "")
 	})

backend/internal/handler/security.go

@@ -80,7 +80,7 @@ func authorizeCustomRelay(method string, target *url.URL, apiFormat string, cont
 		return errors.New("自定义渠道不允许使用该请求方法")
 	}
 	if apiFormat == "openai" {
-		if len(query) != 0 || (!strings.HasSuffix(requestPath, "/responses") && !strings.HasSuffix(requestPath, "/chat/completions") && !strings.HasSuffix(requestPath, "/images/generations") && !strings.HasSuffix(requestPath, "/video/generations") && !strings.HasSuffix(requestPath, "/videos/generations") && !strings.HasSuffix(requestPath, "/contents/generations/tasks")) {
+		if len(query) != 0 || (!strings.HasSuffix(requestPath, "/responses") && !strings.HasSuffix(requestPath, "/chat/completions") && !strings.HasSuffix(requestPath, "/images/generations") && !strings.HasSuffix(requestPath, "/audio/speech") && !strings.HasSuffix(requestPath, "/video/generations") && !strings.HasSuffix(requestPath, "/videos/generations") && !strings.HasSuffix(requestPath, "/contents/generations/tasks")) {
 			return errors.New("自定义渠道不允许访问该上游接口")
 		}
 		return nil

backend/internal/handler/security_test.go

@@ -28,6 +28,7 @@ func TestAuthorizeCustomRelayAllowsModelsAndAgentEndpoints(t *testing.T) {
 		{method: http.MethodGet, target: "https://api.example.com/v1/models", apiFormat: "openai"},
 		{method: http.MethodPost, target: "https://api.example.com/v1/responses", apiFormat: "openai", contentType: "application/json"},
 		{method: http.MethodPost, target: "https://api.example.com/v1/chat/completions", apiFormat: "openai", contentType: "application/json; charset=utf-8"},
+		{method: http.MethodPost, target: "https://api.example.com/v1/audio/speech", apiFormat: "openai", contentType: "application/json"},
 		{method: http.MethodPost, target: "https://api.example.com/v1/video/generations", apiFormat: "openai", contentType: "application/json"},
 		{method: http.MethodGet, target: "https://api.example.com/v1/video/generations/task-1", apiFormat: "openai"},
 		{method: http.MethodPost, target: "https://api.x.ai/v1/videos/generations", apiFormat: "openai", contentType: "application/json"},