[Bug] File links in chat ignore workbench.editorAssociations settings

Bug Description
Title: Respect workbench.editorAssociations for file links in chat Request: When clicking a file link in the chat panel, the extension opens files via showTextDocument() which bypasses editor associations. Please switch to vscode.commands.executeCommand('vscode.open', uri) so markdown files open in preview mode (or whatever editor the user has associated) instead of always opening as plain text. Use case: I have "*.md": "vscode.markdown.preview.editor" in my user settings. It works everywhere except Claude Code chat links.

Environment Info

• Platform: darwin
• Terminal: vscode
• Version: 2.1.110
• Feedback ID: 7dc4990a-d031-4e65-9a94-4786f6ad1689

Errors

[{"error":"Error: 1: Command failed with ERR_STREAM_PREMATURE_CLOSE: code --force --install-extension anthropic.claude-code\nPremature close \n    at pA1 (/$bunfs/root/src/entrypoints/cli.js:1575:4045)\n    at async uA1 (unknown)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-21T18:38:58.542Z"}]