fix(color): eliminate redundant dark: accent modifiers (R-8.29), resolve A-1/A-2/A-9 contrast issues, and implement C11-9 quality gate

refer_landing_page/app/publications/_components/CategoryNav.tsx

@@ -20,7 +20,7 @@ export function CategoryNav({ currentCategory }: CategoryNavProps) {
               className={`px-4 py-2 rounded text-xs font-mono tracking-wider transition-colors ${
                 isActive
                   ? "bg-cobalt-dark text-white dark:text-ivory font-bold"
-                  : "bg-paper text-ink border border-line hover:border-cobalt-dark dark:hover:border-cobalt"
+                  : "bg-paper text-ink border border-line hover:border-cobalt-dark"
               }`}
             >
               {cat.label}