feat(ui): org chart page, issue detail tabs, and UX improvements

- Add org chart page with tree visualization and sidebar nav link
- Restructure issue detail into tabbed layout (comments/activity/sub-issues)
- Persist comment drafts to localStorage with debounce
- Add inline assignee picker to issues list with search
- Fix assignee clear to reset both agent and user assignee
- Fix InlineEditor nesting when rendering markdown content

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

ui/src/pages/MyIssues.tsx

@@ -50,7 +50,7 @@ export function MyIssues() {
               key={issue.id}
               identifier={issue.identifier ?? issue.id.slice(0, 8)}
               title={issue.title}
-              to={`/issues/${issue.identifier ?? issue.id}`}}
+              to={`/issues/${issue.identifier ?? issue.id}`}
               leading={
                 <>
                   <PriorityIcon priority={issue.priority} />