Markdown file links with ~ (home tilde) don't open — tilde not expanded before shell.openPath #573

Problem

Clicking a markdown file link that starts with ~/ does nothing. Example link in chat:

[~/Documents/CraftAgents/note.md](~/Documents/CraftAgents/note.md)

The same link with an absolute path (/Users/me/Documents/...) opens correctly.

Root cause

The tilde is never expanded before being handed to Electron's shell.openPath, which does not do shell-style ~ expansion. The error returned by openPath is swallowed by .then(() => {}), so the click appears to silently do nothing.

Trace through the code:

1. packages/ui/src/components/markdown/linkify.ts — FILE_PATH_TARGET_REGEX explicitly matches ~/ paths, so isFilePathTarget('~/foo.md') is true.
2. packages/ui/src/components/markdown/link-target.ts — resolveMarkdownLinkTarget returns { kind: 'file', path: '~/foo.md' } unchanged.
3. packages/ui/src/components/markdown/Markdown.tsx — the a component calls onFileClick('~/foo.md').
4. apps/electron/src/main/platform.ts:

   openPath: (p) => shell.openPath(p).then(() => {}),

   shell.openPath receives ~/foo.md literally. It returns a non-empty error string ("Failed to open path"), which is discarded.

Steps to reproduce

1. In any chat turn, have the agent output a markdown link with a ~/ path to an existing file, e.g. [~/Documents/test.md](~/Documents/test.md).
2. Click the link.
3. Nothing happens. No error, no toast, no file opens.
4. Replacing ~/ with the full home path makes the same link work.

Expected

Either:

• The tilde is expanded to the user's home directory before shell.openPath, and the file opens, or
• If opening fails, a visible error (toast/log) is shown instead of silently swallowing it.

Suggested fix

Expand ~ to os.homedir() in one of:

• resolveMarkdownLinkTarget (renderer-side, UI package), or
• the Electron main-process openPath wrapper in apps/electron/src/main/platform.ts.

The second option also fixes any other call site that passes ~/... to openPath. Consider also surfacing the error string from shell.openPath instead of discarding it.

Environment

• Craft Agents 0.8.9
• macOS 15 (Darwin 25.3.0), arm64

Related

• fix: decode percent-encoded file paths in markdown link clicks #469 — similar class of bug (percent-encoded paths not decoded before openPath); different root cause but same code path.