Summary

• When AI (e.g. Codex) outputs file references as markdown links (e.g. [App.tsx:1](App.tsx#L1)), clicking them previously navigated the browser to a non-existent URL instead of opening the file in the editor panel
• Added a component override in Markdown.tsx to detect file path hrefs and route them through onFileOpen
• Strips URL fragments (e.g. #L1) before file path detection, since AI models often append line anchors to file paths

Test plan

• Ask Codex to convert a .tex file to markdown — it will reference output files like background.zh.md as markdown links in its response
• Verify clicking these links opens the file in the editor side panel, not navigating to a new browser page
• Verify regular https:// links still open in a new tab as before
• Verify inline code file paths (e.g. App.tsx in backticks) still work as before