Fixes#331
## Summary
- add an optional Markdown preview toggle for markdown files in the
Files tab
- add a word-wrap toggle for the source editor
- escape raw HTML in preview mode and limit preview to plain Markdown
file extensions
## Why
The Files tab only showed raw source, which makes Markdown files harder
to read quickly.
This change adds a lightweight preview/source switch without introducing
a larger viewer registry.
## What Changed
-
`packages/ui/src/components/instance/shell/right-panel/tabs/FilesTab.tsx`
- added `Preview Markdown` / `Show source` toggle for markdown files
- added a word-wrap toggle for the Monaco source viewer
- restricted preview mode to plain Markdown extensions
- escaped raw HTML in markdown preview mode
- `packages/ui/src/components/file-viewer/monaco-file-viewer.tsx`
- added configurable word-wrap support
- `packages/ui/src/components/instance/shell/right-panel/RightPanel.tsx`
- moved file-viewer word-wrap state up so it persists across tab
switches
- `packages/ui/src/components/instance/shell/storage.ts`
- added storage key for file-viewer word wrap
- `packages/ui/src/lib/i18n/messages/*/instance.ts`
- added strings for preview/source and word-wrap controls
## Validation
- `npm run build --workspace @codenomad/ui`
0ba1371348