feat(02-01): register Ranking tab in round detail page + create component stub

- Create src/components/admin/round/ranking-dashboard.tsx (stub with placeholder text)
- Import RankingDashboard in round detail page.tsx
- Add Ranking tab entry guarded by isEvaluation (uses existing BarChart3 icon)
- Add TabsContent block rendering RankingDashboard with competitionId + roundId props

src/app/(admin)/admin/rounds/[roundId]/page.tsx

@@ -89,6 +89,7 @@ import { ProjectStatesTable } from '@/components/admin/round/project-states-tabl
 // SubmissionWindowManager removed — round dates + file requirements in Config are sufficient
 import { FileRequirementsEditor } from '@/components/admin/round/file-requirements-editor'
 import { FilteringDashboard } from '@/components/admin/round/filtering-dashboard'
+import { RankingDashboard } from '@/components/admin/round/ranking-dashboard'
 import { CoverageReport } from '@/components/admin/assignment/coverage-report'
 import { AssignmentPreviewSheet } from '@/components/admin/assignment/assignment-preview-sheet'
 import { AnimatedCard } from '@/components/shared/animated-container'
@@ -842,6 +843,7 @@ export default function RoundDetailPage() {
               { value: 'projects', label: 'Projects', icon: Layers },
               ...(isFiltering ? [{ value: 'filtering', label: 'Filtering', icon: Shield }] : []),
               ...(isEvaluation ? [{ value: 'assignments', label: 'Assignments & Jury', icon: ClipboardList }] : []),
+              ...(isEvaluation ? [{ value: 'ranking', label: 'Ranking', icon: BarChart3 }] : []),
               ...(hasJury && !isEvaluation ? [{ value: 'jury', label: 'Jury', icon: Users }] : []),
               { value: 'config', label: 'Config', icon: Settings },
               ...(hasAwards ? [{ value: 'awards', label: 'Awards', icon: Trophy }] : []),
@@ -2046,6 +2048,13 @@ export default function RoundDetailPage() {
           </TabsContent>
         )}
 
+        {/* ═══════════ RANKING TAB (EVALUATION rounds) ═══════════ */}
+        {isEvaluation && (
+          <TabsContent value="ranking" className="space-y-4">
+            <RankingDashboard competitionId={competitionId} roundId={roundId} />
+          </TabsContent>
+        )}
+
         {/* ═══════════ CONFIG TAB ═══════════ */}
         <TabsContent value="config" className="space-y-6">
           {/* Round Dates */}

src/components/admin/round/ranking-dashboard.tsx

@@ -0,0 +1,14 @@
+'use client'
+
+type RankingDashboardProps = {
+  competitionId: string
+  roundId: string
+}
+
+export function RankingDashboard({ competitionId: _competitionId, roundId: _roundId }: RankingDashboardProps) {
+  return (
+    <div className="text-muted-foreground text-sm p-4">
+      Ranking dashboard coming soon...
+    </div>
+  )
+}