fix: resolve all TypeScript build errors

- Remove unused imports (LoginModal, Zap) and variables
- Fix Language type mismatches across components
- Update HeaderBar interface to use Language type
- Remove unused onLoginClick parameter
- Fix duplicate translation keys by renaming auth steps
- Remove invalid language prop from CommunitySection

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: tinkle-community <tinklefund@gmail.com>

web/src/components/LoginPage.tsx

@@ -57,7 +57,7 @@ export function LoginPage() {
         isHomePage={false}
         currentPage="login"
         language={language}
-        onLanguageChange={(lang) => {}}
+        onLanguageChange={() => {}}
         onPageChange={(page) => {
           console.log('LoginPage onPageChange called with:', page);
           if (page === 'competition') {