[BUG] Desktop preview pane: Reload button does not refresh stale page content after the file changes on disk (macOS)

Environment

• Claude Code desktop app, CLI version 2.1.126
• macOS 26.5.1 (arm64)
• Preview server: python3 -m http.server 8742 --directory bench configured via .claude/launch.json, started with the Preview MCP (preview_start)

Steps to reproduce

1. Serve a static HTML file through the preview server and open it in the desktop app's preview pane (e.g. /review.html).
2. Regenerate the file on disk so its content and mtime change (in our case a Python script rewrites the ~1 MB HTML file).
3. Click the Reload button in the preview pane's toolbar.

Expected

The pane shows the updated file content.

Actual

The pane keeps showing the stale, previously loaded version. Re-selecting the same file in the pane's address/file picker does load the new content, so the server is serving the updated file correctly (plain http.server, sends Last-Modified, no cache headers).

Possibly the Reload button performs a cache-only reload (no revalidation) or doesn't actually reload the webview.

Note: a programmatic location.reload() issued through the Preview MCP (preview_eval) in the same session did pick up the new content, though that may run in a separate browser context from the visible pane.

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🤖 Filed via Claude Code on behalf of the user.