feat(api): 统一公开接口为 /api/v1 前缀

将通用生成、Gemini、可灵、火山、健康检查与 OpenAPI 的推荐入口统一到 /api/v1，并保留历史路径作为兼容别名。同步更新代理配置、接入文档、接口清单和前缀回归测试。\n\n验证：go vet ./...；go test ./...；pnpm openapi；pnpm lint；pnpm test；pnpm build；公开 OpenAPI 71 个方法与接口清单机器比对一致。

apps/api/internal/httpapi/chat_completions_mode_test.go

@@ -58,17 +58,18 @@ func TestPlanTaskResponseTreatsAPIV1EmbeddingAndRerankAsSynchronousCompatibleRes
 	}
 }
 
-func TestPlanTaskResponseKeepsAsyncTaskModeForOtherAPIV1Tasks(t *testing.T) {
-	req := httptest.NewRequest(http.MethodPost, "/api/v1/images/generations", nil)
-	req.Header.Set("X-Async", "true")
-
-	plan := planTaskResponse("images.generations", false, map[string]any{"stream": true}, req)
-
-	if !plan.asyncMode {
-		t.Fatal("non-chat /api/v1 task endpoints should keep X-Async task mode")
+func TestPlanTaskResponseUsesCompatibleAPIV1MediaResponsesAndKeepsAsyncOptIn(t *testing.T) {
+	defaultRequest := httptest.NewRequest(http.MethodPost, "/api/v1/images/generations", nil)
+	defaultPlan := planTaskResponse("images.generations", true, map[string]any{}, defaultRequest)
+	if defaultPlan.asyncMode || !defaultPlan.compatibleMode {
+		t.Fatalf("canonical /api/v1 media endpoints should default to synchronous compatible responses, got %+v", defaultPlan)
 	}
-	if plan.compatibleMode {
-		t.Fatal("non-compatible /api/v1 task endpoints should not return OpenAI-compatible payloads")
+
+	asyncRequest := httptest.NewRequest(http.MethodPost, "/api/v1/images/generations", nil)
+	asyncRequest.Header.Set("X-Async", "true")
+	asyncPlan := planTaskResponse("images.generations", true, map[string]any{}, asyncRequest)
+	if !asyncPlan.asyncMode || !asyncPlan.compatibleMode {
+		t.Fatalf("canonical /api/v1 media endpoints should keep compatible mode when X-Async is enabled, got %+v", asyncPlan)
 	}
 }