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/app/(portal)/portal/login/page.tsx

@@ -26,7 +26,7 @@ export default function PortalLoginPage() {
 
       if (!res.ok) {
         const data = await res.json().catch(() => ({}));
-        setError((data as any).error ?? 'Something went wrong. Please try again.');
+        setError((data as { error?: string }).error ?? 'Something went wrong. Please try again.');
         return;
       }
 

src/app/(portal)/portal/verify/page.tsx

@@ -16,7 +16,7 @@ export default function PortalVerifyPage() {
     const token = searchParams.get('token');
 
     if (!token) {
-      router.replace('/portal/login?error=missing_token' as any);
+      router.replace('/portal/login?error=missing_token');
       return;
     }