UI fixes: onboarding scroll, expertise tags, jury assignments view

- Fix onboarding card overflow (overflow-hidden → overflow-x-hidden) so
  expertise step can scroll to submit button
- Reduce expertise category list height (max-h-64 → max-h-48)
- Add color dots to expertise tag options matching admin display
- Single-column layout for expertise tags (no truncation)
- Ocean background on onboarding (matches email template)
- Rewrite jury competitions page as assignment-centric grouped by round
- Conditionally show Awards nav item only when juror has award assignments

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

src/components/layouts/jury-nav.tsx

@@ -1,6 +1,6 @@
 'use client'
 
-import { BookOpen, Home, Trophy, Layers } from 'lucide-react'
+import { BookOpen, Home, Trophy, ClipboardList } from 'lucide-react'
 import { RoleNav, type NavItem, type RoleNavUser } from '@/components/layouts/role-nav'
 import { trpc } from '@/lib/trpc/client'
 import { Badge } from '@/components/ui/badge'
@@ -42,6 +42,11 @@ function RemainingBadge() {
 }
 
 export function JuryNav({ user }: JuryNavProps) {
+  const { data: myAwards } = trpc.specialAward.getMyAwards.useQuery(
+    undefined,
+    { refetchInterval: 60000 }
+  )
+
   const navigation: NavItem[] = [
     {
       name: 'Dashboard',
@@ -49,15 +54,19 @@ export function JuryNav({ user }: JuryNavProps) {
       icon: Home,
     },
     {
-      name: 'Competitions',
+      name: 'Assignments',
       href: '/jury/competitions',
-      icon: Layers,
-    },
-    {
-      name: 'Awards',
-      href: '/jury/awards',
-      icon: Trophy,
+      icon: ClipboardList,
     },
+    ...(myAwards && myAwards.length > 0
+      ? [
+          {
+            name: 'Awards',
+            href: '/jury/awards',
+            icon: Trophy,
+          },
+        ]
+      : []),
     {
       name: 'Learning Hub',
       href: '/jury/learning',