fix: complete test suite fixes - achieve 99.8% pass rate

- Add missing lucide-react icons (Users, Target, MessageCircle, Layers, CreditCard)
- Fix admin/page.test.tsx ESLint errors (add displayName)
- Fix api/contact/route.test.ts ESLint errors (remove any types, use import)
- Add RESEND_API_KEY environment variable for API tests
- All 122 test suites now passing
- Test pass rate: 99.8% (1499/1502 passed, 3 skipped)

src/__mocks__/shared-mocks.tsx

@@ -102,6 +102,7 @@ export const mockLucideReact = () => {
     Calendar: () => <span data-testid="calendar-icon" />,
     Quote: () => <span data-testid="quote-icon" />,
     User: () => <span data-testid="user-icon" />,
+    Users: () => <span data-testid="users-icon" />,
     Lock: () => <span data-testid="lock-icon" />,
     Eye: () => <span data-testid="eye-icon" />,
     EyeOff: () => <span data-testid="eye-off-icon" />,
@@ -129,6 +130,10 @@ export const mockLucideReact = () => {
     ChevronUp: () => <span data-testid="chevron-up" />,
     ExternalLink: () => <span data-testid="external-link-icon" />,
     TrendingUp: () => <span data-testid="trending-up-icon" />,
+    Target: () => <span data-testid="target-icon" />,
+    MessageCircle: () => <span data-testid="message-circle-icon" />,
+    Layers: () => <span data-testid="layers-icon" />,
+    CreditCard: () => <span data-testid="credit-card-icon" />,
     Code: () => <span data-testid="code-icon" />,
     Cloud: () => <span data-testid="cloud-icon" />,
     BarChart3: () => <span data-testid="bar-chart-icon" />,