refactor: defaultTemperature/defaultTopP 从 Provider 级别迁移到 Model 级别

- 删除所有 Provider 顶层的 defaultTemperature / defaultTopP
- 为所有对话类模型添加 model 级别的推荐温度参数（基于官方文档）
- volcengine：将 extra 内温度参数提升到模型顶层正式字段
- presetDataVersion 7→8

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

compute/providers/baidu.json

@@ -10,8 +10,6 @@
   "status": "unconfigured",
   "priceCurrency": "CNY",
   "services": ["chat", "reasoning"],
-  "defaultTemperature": 1,
-  "defaultTopP": 1,
   "models": [
     {
       "modelName": "ernie-5.0-thinking-latest",
@@ -29,6 +27,8 @@
       ],
       "inputPrice": 8,
       "outputPrice": 32,
+      "defaultTemperature": 1,
+      "defaultTopP": 1,
       "extra": {}
     },
     {
@@ -45,6 +45,8 @@
       ],
       "inputPrice": 0.8,
       "outputPrice": 3.2,
+      "defaultTemperature": 1,
+      "defaultTopP": 1,
       "extra": {}
     }
   ]