refactor(ui): strip all dark: Tailwind classes (single-theme product)

Mechanical sweep of 41 files via `perl -i -pe 's{\s+dark:[\w:/\[\]\.\-]+}{}g'`.
All dark: variants were paired with light-mode counterparts already; no
elements relied on a dark:-only style.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/components/admin/round/project-states-table.tsx

@@ -290,8 +290,8 @@ export function ProjectStatesTable({ competitionId, roundId, roundStatus, compet
     <div className="space-y-4">
       {/* Finalization hint for closed rounds */}
       {(roundStatus === 'ROUND_CLOSED' || roundStatus === 'ROUND_ARCHIVED') && (
-        <div className="flex items-center gap-2 rounded-lg border border-blue-200 bg-blue-50 dark:border-blue-800 dark:bg-blue-950/20 px-4 py-3 text-sm">
-          <span className="text-blue-700 dark:text-blue-300">
+        <div className="flex items-center gap-2 rounded-lg border border-blue-200 bg-blue-50 px-4 py-3 text-sm">
+          <span className="text-blue-700">
             This round is closed. Use the <strong>Finalization</strong> tab to review proposed outcomes and confirm advancement.
           </span>
         </div>