feat(ui): project details panel + compact/responsive cards; rename Sentinel→Yerin (red); migrate research_notes

- Project card expands to show description + status + dates (was only the research stub)
- Cards compacted + responsive (actions wrap on narrow)
- Sentinel renamed Yerin everywhere (#/yerin, red 'Sage of the Endless Sword' theme + red sidebar dot)
- void1 importer now carries research_notes/last_researched_at (was dropped)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

public/components/sidebar.js

@@ -90,7 +90,7 @@ export function renderSidebar(root) {
     ),
     el('div', { class: 'sb-section' },
       el('div', { class: 'sb-title' }, 'Agents'),
-      navItem('Sentinel', '/sentinel', { dot: 'ok' }),
+      navItem('Yerin', '/yerin', { dot: 'yerin' }),
       navItem('Little Blue', '/little-blue', { dot: 'lb' })
     ),
     el('div', { class: 'sb-section' },