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>

packages/api/src/router/user-self-service-procedure-support.ts

@@ -61,8 +61,11 @@ export async function getDashboardLayout(ctx: UserSelfServiceContext) {
     select: { dashboardLayout: true, updatedAt: true },
   });
 
+  const normalized = user?.dashboardLayout
+    ? normalizeDashboardLayout(user.dashboardLayout)
+    : null;
   return {
-    layout: user?.dashboardLayout ? normalizeDashboardLayout(user.dashboardLayout) : null,
+    layout: normalized?.widgets.length ? normalized : null,
     updatedAt: user?.updatedAt ?? null,
   };
 }