Windows: context menu on file links mishandles non-ASCII paths (URL-encoded path sent to Explorer / clipboard)

Environment

• OS: Windows 11 Pro (10.0.26200)
• Claude Code on Windows
• Project path contains Japanese characters (under OneDrive)

Bug

When right-clicking a markdown file link in the chat whose target contains non-ASCII characters (Japanese):

1. 「エクスプローラーで表示」 (Reveal in Explorer): silently does nothing.
2. 「パスをコピー」 (Copy path): copies the path with non-ASCII segments percent-encoded (e.g., %E5%9F%B7%E7%AD%86...). Pasting into Explorer's address bar fails, because Explorer treats %XX as literal characters.

Example copied path for a file at 日本語プロジェクト/日本語フォルダ/日本語サブフォルダ/日本語ファイル名.docx:

C:\Users\USER\OneDrive\ドキュメント\Claude\Projects\日本語プロジェクト/%E6%97%A5%E6%9C%AC%E8%AA%9E%E3%83%95%E3%82%A9%E3%83%AB%E3%83%80/%E6%97%A5%E6%9C%AC%E8%AA%9E%E3%82%B5%E3%83%96%E3%83%95%E3%82%A9%E3%83%AB%E3%83%80/%E6%97%A5%E6%9C%AC%E8%AA%9E%E3%83%95%E3%82%A1%E3%82%A4%E3%83%AB%E5%90%8D.docx

Note: only the relative-path portion (from the markdown link href) is percent-encoded; the project root prefix is preserved as raw Japanese. This indicates the path is assembled from a percent-encoded href and handed to OS APIs without being URL-decoded first.

Reproduction

1. On Windows, use a project whose path contains Japanese characters.
2. Have Claude Code create or reference a file under a Japanese subfolder.
3. Right-click the resulting markdown link in the chat → try "エクスプローラーで表示" or "パスをコピー".

Expected

• "Reveal in Explorer" opens Explorer with the file selected.
• "Copy path" returns the raw Windows path (no percent-encoding).

Current workaround

Ask Claude Code to print the decoded absolute path as plain text, then copy that manually.

Likely fix

URL-decode the link target before invoking the Shell/Explorer APIs and before placing it on the clipboard.