Repo-relative file links in multi-repo threads resolve against the workspace root and fail to open

[dotrahat]

Symptom

In a multi-repo project whose workspace root is a parent folder, clicking a repo-relative file path in an agent reply opens the preview panel with an error:

Failed to read workspace file '.graft/config.json' in '/home/cvl'.

The file exists, but at /home/cvl/unitree_sim_isaaclab/.graft/config.json, one level down in a repo root.

T3 Code 0.0.42 (Linux AppImage), built from multi-repo-workspaces @ 1d386b99a, local environment.

Repro

1. Have a project with workspace root /home/<user> and repo roots /home/<user>/<repo-1>, /home/<user>/<repo-2>, and three more.
2. Ask the agent about uncommitted changes in one repo. It runs cd /home/<user>/<repo-1> && git status and writes the path as `.graft/config.json`.
3. Click the file chip for that path.
4. The preview reads /home/<user>/.graft/config.json, which does not exist.

Cause

In a chat message, a relative path resolves against the workspace root, not against a repo root:

• resolveMarkdownFileLinkTarget joins the relative path onto the workspace root (apps/web/src/markdown-links.ts:83).
• buildFileLinkMetaFromTarget then looks for the repo that contains the resulting path (markdown-links.ts:146). /home/cvl/.graft/config.json is not inside any repo root, so the preview reads from the workspace root (FilePreviewPanel.tsx:958).

The path is also ambiguous: .graft/config.json can exist in multiple repo roots (<repo-1> and <repo-2>).

[dotrahat]

If my setup is wrong or I am making some mistake unknowingly, please let me know. Thank you

[LoganRupe]

Hey @dotrahat, your setup's fine. A workspace root with the repos sitting under it is exactly what multi-repo projects are meant to support. Thanks for the clear write-up and the repro, it made this easy to trace.

Your diagnosis is right. The chat resolves relative paths against the workspace root, and a git-relative path like .graft/config.json can live in more than one repo, so the client can't pick the right one by itself.

I saw #303 before you closed it, and I think it's the right approach: ask multi-repo sessions for absolute paths, and pass the repo roots through for inline-code links. If you want to reopen it when it's ready, I'd be glad to review it. The only thing I'd add is the same roots argument at the two fallback call sites in ChatMarkdown.tsx (around lines 2863 and 3073).

Thanks again!

[dotrahat]

@LoganRupe Thanks soo much for such a quick response & maintaining it. Ok, I'll reopen once I'm ready.