[Bug]: Case-distinct POSIX Markdown file link opens the wrong workspace file

[AksharP5]

Before submitting

• I searched existing issues and did not find a duplicate.
• I included enough detail to reproduce or investigate the problem.

Area

apps/web

Steps to reproduce

1. Create two sibling directories whose names differ only by case:

mkdir -p /tmp/t3code-case-test.XJVIDu/Project
mkdir -p /tmp/t3code-case-test.XJVIDu/project
printf 'WRONG: workspace file from uppercase Project\n' > /tmp/t3code-case-test.XJVIDu/Project/probe.txt
printf 'CORRECT: sibling file from lowercase project\n' > /tmp/t3code-case-test.XJVIDu/project/probe.txt

2. Open /tmp/t3code-case-test.XJVIDu/Project as the T3 Code project.

3. Send this Markdown in a chat message:

   [case probe](/tmp/t3code-case-test.XJVIDu/project/probe.txt)

4. Hover the rendered file link, then left-click it.

Expected behavior

The lowercase sibling should not be classified as part of the uppercase workspace. The tooltip should preserve the absolute lowercase path, and a normal click should open that absolute path through the preferred editor.

Actual behavior

T3 Code displays the link as Project/probe.txt and treats it as workspace-relative. A normal click opens Project/probe.txt in the right-panel preview, even though the link targets the separate lowercase project directory.

The agent can read the requested lowercase file as CORRECT while the T3 preview opens the uppercase file containing WRONG.

Impact

Minor bug or occasional failure

Version or commit

0.0.30-nightly (20260728.928); also reproducible on main @ 2deea7a

Environment

Arch Linux, Linux 7.0.10-arch1-1, x86_64

Logs or stack traces

Screenshots, recordings, or supporting files

Before — outside sibling misclassified

After — outside sibling remains absolute

After — inside-workspace display remains relative

Workaround

No response