feat(ui): make edited file references clickable in desktop session UI

[anduimagui]

Issue for this PR

Closes #13430

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

It makes file references in session output clickable so users can open files directly from agent responses and tool results.

The change adds shared openFilePath plumbing, detects file-like inline code references (including path:line and file://...) in markdown, and wires clicks in edit/write/apply_patch file labels to open the file in the review panel.

Related work and how this is different (plain English)

• Related issue: [FEATURE]: Clickable file paths in agent responses #11432 asked for clickable file paths in agent responses.
• Related issue: [FEATURE]: Modified Files list clickable #14013 asked for the modified files list to be clickable.
• Related PR: feat: add clickable file paths in agent responses (web UI only) #11429 focuses on making file paths clickable in agent responses for web UI.
• Related PR: feat(tui): make modified files in sidebar clickable #14016 focuses on clickable modified files in TUI sidebar.

How this PR differs:

• This PR targets the app/ui path used by desktop/web session rendering and tool cards.
• It links inline code-style file references in markdown (for example src/foo.ts, src/foo.ts:42, and file://...) and also makes filenames inside edit/write/apply_patch cards clickable.
• Clicking opens the file in the existing review/file flow via shared openFilePath plumbing.
• It does not implement TUI sidebar behavior; that scope is covered by feat(tui): make modified files in sidebar clickable #14016.

How did you verify your code works?

• bun run typecheck in packages/ui
• pre-push hook (bun turbo typecheck) passed on push

Screenshots / recordings

• N/A

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR

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