[Zhangs-11]

Problem

With the UI set to 简体中文 or 繁體中文, three places in the file panel stay English:

• After an upload, the result counts' tooltips and labels read 2 uploaded, 1 skipped, 1 failed (components/FileExplorer.tsx).
• When an image, audio or video preview cannot load, the panel shows Failed to load image / audio / video (components/FileViewer.tsx).
• While the file tree loads, it shows Loading files... (components/FileExplorer.tsx), although the files.loading message with that text already exists in every language.

The rest of both panels is already translated (the upload buttons, the conflict prompt, Add all uploaded files to chat, …).

Reproduce on main

1. Switch the UI to 简体中文.
2. Upload two files to the project root from the Files toolbar, then hover the green count: 2 uploaded. Upload them again and pick 跳过已有文件: 2 skipped.
3. Open a file named broken.png that is not really a PNG: Failed to load image.

Fix

• Six new files.* messages in en, zh-CN and zh-TW, with {count} as a parameter as docs/i18n.md asks. The English strings are exactly the old ones.
• The file tree's loading line uses the existing files.loading message.

Checks

• npm test (2869 passed, 0 failed), node_modules/.bin/tsc --noEmit, npm run lint.
• In headless Chrome with 简体中文: the broken image shows 图片加载失败, an upload of two files shows 已上传 2 个, and uploading them again with 跳过已有文件 shows 已跳过 2 个. The failed count uses the same code path; I did not trigger a failed upload locally. The loading line is only on screen for a moment and was checked in code.

🤖 Generated with Claude Code

[agegr]

Thanks. I checked it: the English strings are unchanged, the six new keys are in all three languages with {count} as the parameter, and the zh-TW wording matches the existing 略過現有檔案. tsc, lint and tests pass, and it merges cleanly with #1378, #1382 and #1383 in any order.