PAP-57: IA Phase 2 — rename user-facing "Issues" → "Tasks" copy

Copy-only sweep across ui/src: nav (sidebar + mobile), Tasks list page
(headings, breadcrumbs, buttons, empty states, filters, column headers,
toasts, aria-labels), task detail, dialogs, command palette, inbox,
search, dashboards, project/agent/workspace pages, recovery/blocked
notices, and design-guide demos.

Routes stay at /issues; internal symbols (Issue, issueId, queryKeys,
kind: "issue"), API fields, and backend-matched protocol strings
(successful-run-handoff notice bodies) are unchanged. Tests updated to
match the new copy. Developer-only *UxLab/*Perf harness pages left as-is.

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

ui/src/components/ProjectWorkspaceSummaryCard.tsx

@@ -227,7 +227,7 @@ export function ProjectWorkspaceSummaryCard({
         {summary.issues.length > 0 ? (
           <div className="space-y-2">
             <div className="text-[11px] font-medium uppercase tracking-[0.14em] text-muted-foreground">
-              Linked issues
+              Linked tasks
             </div>
             <div className="flex flex-wrap gap-2">
               {visibleIssues.map((issue) => (