feat(compute): 补齐媒体生成 provider 能力声明（Seedream/Seedance/快乐马） (#34)

- volcengine：services 增 image_gen/video_gen；新增 doubao-seedream-4-0-250828（真 img2img/多图融合）与 doubao-seedance-2-0-260128（多素材视频）模型
- dashscope：新增快乐马 happyhorse-1.0-t2v/i2v/r2v 视频模型
- service-map：默认 image_gen→minimax/image-01、video_gen→minimax/MiniMax-Hailuo-2.3（指向已有内置工具适配器的后端）

使算力配置 UI 能展示这些 provider 的图像/视频能力标签与模型，用户填 key 时即可显式知晓其用途。

compute/providers/dashscope.json

@@ -689,6 +689,78 @@
       "defaultTemperature": 0.65,
       "defaultTopP": 0.8,
       "extra": {}
+    },
+    {
+      "modelName": "happyhorse-1.0-t2v",
+      "displayName": "快乐马 1.0 文生视频",
+      "serviceType": [
+        "video_gen"
+      ],
+      "description": "阿里 HappyHorse 文生视频，原生音视频联合生成，最长 15s，支持多语种口型",
+      "capabilities": [
+        "video_generation",
+        "text_to_video",
+        "chinese_optimized",
+        "high_quality"
+      ],
+      "extra": {
+        "endpoint": "/services/aigc/video-generation/video-synthesis",
+        "asyncHeader": "X-DashScope-Async",
+        "taskQueryEndpoint": "/tasks",
+        "maxVideoDuration": 15,
+        "supportedResolutions": [
+          "720P",
+          "1080P"
+        ]
+      }
+    },
+    {
+      "modelName": "happyhorse-1.0-i2v",
+      "displayName": "快乐马 1.0 图生视频",
+      "serviceType": [
+        "video_gen"
+      ],
+      "description": "阿里 HappyHorse 图生视频（首帧），宽高比自动跟随输入首帧",
+      "capabilities": [
+        "video_generation",
+        "image_to_video",
+        "chinese_optimized"
+      ],
+      "extra": {
+        "endpoint": "/services/aigc/video-generation/video-synthesis",
+        "asyncHeader": "X-DashScope-Async",
+        "taskQueryEndpoint": "/tasks",
+        "maxVideoDuration": 15,
+        "supportedResolutions": [
+          "720P",
+          "1080P"
+        ]
+      }
+    },
+    {
+      "modelName": "happyhorse-1.0-r2v",
+      "displayName": "快乐马 1.0 参考生视频",
+      "serviceType": [
+        "video_gen"
+      ],
+      "description": "阿里 HappyHorse 参考生视频，支持最多 9 张参考图（多主体/元素一致性）",
+      "capabilities": [
+        "video_generation",
+        "reference_to_video",
+        "multi_image",
+        "chinese_optimized"
+      ],
+      "extra": {
+        "endpoint": "/services/aigc/video-generation/video-synthesis",
+        "asyncHeader": "X-DashScope-Async",
+        "taskQueryEndpoint": "/tasks",
+        "maxReferenceImages": 9,
+        "maxVideoDuration": 15,
+        "supportedResolutions": [
+          "720P",
+          "1080P"
+        ]
+      }
     }
   ]
 }