feat: user invite flow, deactivate/delete, favicon, dashboard loading fix, admin full-width

- Invite flow: admin can invite users by email with role selection; accept-invite page
  sets password and creates the account; 72-hour token expiry; E2E tests
- User deactivate/reactivate/delete: new tRPC procedures + UI buttons; deactivation
  revokes all active sessions immediately; delete cascades vacation/broadcast records;
  isActive field added via migration 20260402000000_user_isactive
- Auth: block login for inactive users with audit entry
- Favicon: SVG favicon + ICO/PNG fallbacks (16, 32, 180, 192, 512px); manifest updated
- Dashboard: GridLayout dynamic-import loading skeleton prevents blank dark area
  on first login before react-grid-layout chunk is cached
- Admin users: remove max-w-5xl constraint so table uses full page width
- Dev: docker container restart workflow documented in LEARNINGS.md; Prisma generate
  must run inside the container after schema changes (named node_modules volume)

Co-Authored-By: claude-flow <ruv@ruv.net>

apps/web/src/components/dashboard/DashboardClient.tsx

@@ -23,10 +23,21 @@ function WidgetFallback() {
   );
 }
 
+function GridLayoutSkeleton() {
+  return (
+    <div className="grid grid-cols-2 gap-3 p-3">
+      {Array.from({ length: 4 }).map((_, i) => (
+        <div key={i} className="h-48 shimmer-skeleton rounded-2xl" />
+      ))}
+    </div>
+  );
+}
+
 // Dynamic import — no WidthProvider (uses findDOMNode, broken in React 18 strict mode).
 // We measure container width ourselves via ResizeObserver and pass it as a prop.
 const GridLayout = dynamic(() => import("react-grid-layout").then((m) => m.Responsive), {
   ssr: false,
+  loading: () => <GridLayoutSkeleton />,
 });
 
 function renderWidget(