i18n: model folder list shows English names without Chinese translations or tooltips

### Problem
The model folder list in the desktop app shows English folder names (checkpoints, loras, vae, text_encoders, etc.) without Chinese labels or tooltips. Users cannot understand what each folder is for.

### Current behavior
- Model folder list shows raw backend folder names with counts (e.g., "checkpoints 0", "loras 0")
- No Chinese display names
- No hover tooltips explaining each folder's purpose

### Expected behavior
- Chinese display names for each model folder
- Hover tooltips describing what each folder stores (e.g., "基础模型文件，存放 Stable Diffusion 等主模型，是图像生成的核心")

### Proposed solution
Apply `formatDisplayName()` (already in `useModelTypes.ts`) to the model folder list rendering in the desktop app, or add Chinese localization to the backend API that returns folder names.

┆Issue is synchronized with this [Notion page](https://www.notion.so/Issue-12108-i18n-model-folder-list-shows-English-names-without-Chinese-translations-or-tooltips-35b6d73d365081929b96ffd9f994ccb8) by [Unito](https://www.unito.io)