feat(providers): add provider categorization system

- Add ProviderCategory type with official, cn_official, aggregator, third_party, and custom categories
- Update Provider interface and Rust struct to include optional category field
- Enhance ProviderForm to automatically sync category when selecting presets
- Improve PresetSelector to show category-based styling and hints
- Add category classification to all provider presets
- Support differentiated interactions (e.g., hide API key input for official providers)
- Maintain backward compatibility with existing configurations

src/types.ts

@@ -1,8 +1,17 @@
+export type ProviderCategory =
+  | "official" // 官方
+  | "cn_official" // 国产官方
+  | "aggregator" // 聚合网站
+  | "third_party" // 第三方供应商
+  | "custom"; // 自定义
+
 export interface Provider {
   id: string;
   name: string;
   settingsConfig: Record<string, any>; // 应用配置对象：Claude 为 settings.json；Codex 为 { auth, config }
   websiteUrl?: string;
+  // 新增：供应商分类（用于差异化提示/能力开关）
+  category?: ProviderCategory;
   createdAt?: number; // 添加时间戳（毫秒）
 }