Fix all ESLint errors: remove unused imports, replace any types

- Remove ~60 unused imports and variables across 88 files
- Replace ~80 `any` type annotations with proper types (unknown,
  Record<string, unknown>, or specific types)
- Prefix unused callback args with underscore
- Fix unescaped JSX entities
- Lint now passes cleanly (0 errors, 2 intentional img warnings)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/components/portal/portal-card.tsx

@@ -41,7 +41,7 @@ export function PortalCard({
   );
 
   if (href) {
-    return <Link href={href as any}>{content}</Link>;
+    return <Link href={href}>{content}</Link>;
   }
 
   return content;