- Switch TaskSlideOver from absolute to fixed positioning so it overlays
the viewport instead of fighting with phase panel scroll
- Render task descriptions as rich HTML via markdownToSafeHtml (markdown
→ tiptap JSON → HTML roundtrip) with prose typography classes
- Move TaskSlideOver render to ExecutionProvider level in ExecutionTab
- Remove unnecessary relative overflow-hidden wrapper from PhaseDetailPanel
- Export markdownToSafeHtml from markdown-to-tiptap utility