chore(internal-testing): 退役内置 provider；bump presetDataVersion to 61 (#26)

* chore(internal-testing): 退役内置 provider；bump presetDataVersion to 52

internal-testing 一直作为内测阶段的硬编码 provider 存在，现在客户端已切换到
登录后绑定 desirecore-cloud（NewAPI 网关）方案，internal-testing 不再需要。

从此 commit 起：
- compute/providers/internal-testing.json 删除
- _index.json 移除 internal-testing 条目
- presetDataVersion 51 → 52，触发客户端重新合并预置

客户端需配套实现 retired-providers 清理逻辑：在 mergeBuiltinIfNewer 之后
执行一次性清理，移除本地 compute.json 中残留的 provider-internal-testing-001
+ secrets.json#internal-testing。

* chore: bump preset data version to 61

* feat: 增量同步 16 个厂商旗舰模型 (首批精选)

首次从 OpenRouter 增量同步，覆盖 13 家厂商的最新旗舰：

概要
---
- 新增 .sync-watermark 水位线文件 (1782276303 / 2026-06-24)
- presetDataVersion: 61 → 62
- 校验 70/70 全部通过

新增模型
---
OpenAI:     gpt-image-2 (image_gen), gpt-5.5, gpt-5.4
Anthropic:  claude-fable-5, claude-opus-4.8
Google:     gemini-3.5-flash, gemini-3.1-flash-image (Nano Banana 2)
DeepSeek:   deepseek-v4-pro
Qwen:       qwen3.7-max, qwen3.7-plus
MiniMax:    MiniMax-M3
Moonshot:   kimi-k2.7-code
Zhipu:      glm-5.2
xAI:        grok-4.3
Mistral:    mistral-medium-3.5
Tencent:    hy3-preview
Cohere:     north-mini-code

后续机制
---
每日 10:00 心跳检查 OpenRouter 新模型，对比 .sync-watermark
增量入库，有更新才提 PR，无更新静默。

api-providers/image-understanding/_index.json

@@ -1,4 +1,4 @@
 {
   "description": "image_understanding 工具后端加载顺序索引",
-  "order": ["configured-vision-openai", "configured-vision-anthropic", "minimax"]
+  "order": ["configured-vision-openai", "configured-vision-anthropic"]
 }

api-providers/image-understanding/minimax.json

@@ -1,18 +0,0 @@
-{
-  "id": "minimax",
-  "name": "MiniMax 图像理解（内测网关）",
-  "capability": "image_understanding",
-  "enabled": false,
-  "builtin": true,
-  "priority": 30,
-  "endpoint": "${baseUrl}/understand_image",
-  "method": "POST",
-  "baseUrlRef": "internal-testing",
-  "auth": { "type": "bearer" },
-  "request": {
-    "imageMode": "url",
-    "bodyTemplate": { "prompt": "${prompt}", "image_url": "${imageUrl}" }
-  },
-  "response": { "textPath": "text" },
-  "timeoutMs": 30000
-}

api-providers/web-search/_index.json

@@ -1,4 +1,4 @@
 {
   "description": "web_search 工具后端加载顺序索引",
-  "order": ["tavily", "serper", "minimax"]
+  "order": ["tavily", "serper"]
 }

api-providers/web-search/minimax.json

@@ -1,20 +0,0 @@
-{
-  "id": "minimax",
-  "name": "MiniMax 搜索（内测网关）",
-  "capability": "web_search",
-  "enabled": false,
-  "builtin": true,
-  "priority": 30,
-  "endpoint": "${baseUrl}/web_search",
-  "method": "POST",
-  "baseUrlRef": "internal-testing",
-  "auth": { "type": "bearer" },
-  "request": {
-    "bodyTemplate": { "query": "${query}", "num_results": "${maxResults}" }
-  },
-  "response": {
-    "resultsPath": "results",
-    "item": { "titlePath": "title", "urlPath": "url", "snippetPath": "content" }
-  },
-  "timeoutMs": 10000
-}