[FEATURE]: Make file references in assistant responses clickable #17816

Feature hasn't been suggested before.

• I have verified this feature I'm about to request hasn't been suggested before.

Describe the enhancement you want to request

Responses often mention files and line numbers in plain text. I'd like those references to become clickable in the desktop app so the referenced file can be opened directly, and the app can jump to the referenced line when one is present.

Proposed behavior:

• File.ext opens the file
• File.ext:123 opens the file at line 123
• File.ext:123-130 opens the file and selects that range
• paths with / or \ should work too
• if a basename matches multiple files, show a picker instead of guessing

Scope:

• desktop app only
• conservative matching rules to avoid false positives
• no major visual redesign; just make recognized file references interactive

This would reduce friction when reading assistant output and make file navigation much faster.

I already have a working local implementation of this and can open a PR if this approach is aligned. I've attached a short video showing the behavior.