feat: 拆分 providers.json 为按 Provider 独立文件

将 compute/providers.json（54KB, 14 providers, 99 models）拆分为
compute/providers/ 目录下的独立 JSON 文件，便于维护和按需更新。

新增文件：
- compute/providers/_index.json — 加载顺序索引（保证 digest 确定性）
- compute/providers/{provider}.json × 14 — 各 provider 独立配置

保留 compute/providers.json 供旧客户端向后兼容（过渡期）。

presetDataVersion: 2 → 3

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

compute/providers/kling.json

@@ -0,0 +1,91 @@
+{
+  "id": "provider-kling-001",
+  "provider": "kling",
+  "label": "可灵 AI",
+  "baseUrl": "https://api.klingai.com/v1",
+  "apiFormat": "openai-completions",
+  "apiKeyRef": "kling",
+  "apiKeyVerified": false,
+  "enabled": false,
+  "status": "unconfigured",
+  "services": [
+    "video_gen"
+  ],
+  "models": [
+    {
+      "modelName": "kling-v2-5-turbo",
+      "displayName": "可灵 V2.5 Turbo",
+      "serviceType": "video_gen",
+      "description": "可灵最新视频生成模型，高性价比",
+      "capabilities": [
+        "video_generation",
+        "chinese_optimized",
+        "high_quality",
+        "fast"
+      ],
+      "extra": {
+        "maxVideoDuration": 10,
+        "supportedResolutions": [
+          "720p",
+          "1080p"
+        ],
+        "pricePerGeneration": 1.5
+      }
+    },
+    {
+      "modelName": "kling-v2-5-turbo-pro",
+      "displayName": "可灵 V2.5 Turbo Pro",
+      "serviceType": "video_gen",
+      "description": "可灵高品质视频生成",
+      "capabilities": [
+        "video_generation",
+        "chinese_optimized",
+        "ultra_quality"
+      ],
+      "extra": {
+        "maxVideoDuration": 10,
+        "supportedResolutions": [
+          "1080p",
+          "4k"
+        ],
+        "pricePerGeneration": 2.5
+      }
+    },
+    {
+      "modelName": "kling-v2",
+      "displayName": "可灵 V2",
+      "serviceType": "video_gen",
+      "description": "可灵文生视频旗舰模型",
+      "capabilities": [
+        "video_generation",
+        "chinese_optimized",
+        "high_quality"
+      ],
+      "extra": {
+        "maxVideoDuration": 10,
+        "supportedResolutions": [
+          "720p",
+          "1080p"
+        ]
+      }
+    },
+    {
+      "modelName": "kling-v2-master",
+      "displayName": "可灵 V2 Master",
+      "serviceType": "video_gen",
+      "description": "可灵最高品质视频生成",
+      "capabilities": [
+        "video_generation",
+        "chinese_optimized",
+        "ultra_quality"
+      ],
+      "extra": {
+        "maxVideoDuration": 10,
+        "supportedResolutions": [
+          "1080p",
+          "4k"
+        ]
+      }
+    }
+  ]
+}