fix: avoid global mock clearing in Navigation tests

- Add explicit next/link mock for consistency
- Remove mock.clearAllMocks() from beforeEach/afterEach
- Navigation tests now rely on module mocks set at file level
- Prevents interference with other test files

src/__tests__/Navigation.test.tsx

@@ -9,6 +9,13 @@ import { describe, it, expect, mock, beforeEach, afterEach } from 'bun:test'
 import { render, screen, waitFor } from '@testing-library/react'
 import Navigation from '@/components/Navigation'
 
+// Mock next/link
+mock.module('next/link', () => ({
+  default: ({ children, href }: { children: React.ReactNode; href: string }) => (
+    <a href={href}>{children}</a>
+  ),
+}))
+
 // Mock the SessionProvider
 mock.module('@/components/SessionProvider', () => ({
   useSession: mock(() => {}),
@@ -28,8 +35,9 @@ import { useSession } from '@/components/SessionProvider'
 
 describe('Epic 1: Navigation Component', () => {
   beforeEach(() => {
-    mock.clearAllMocks();
+    // Don't clear all mocks as it might affect bun-setup.ts
-    (global.fetch).mockImplementation(async (url) => {
+    // Set up default fetch mock
+    (global.fetch as any).mockImplementation?.(async (url: any) => {
       if (url?.toString().includes('/api/users/')) {
         return new Response(JSON.stringify({ role: 'player' }), {
           status: 200,
@@ -41,7 +49,8 @@ describe('Epic 1: Navigation Component', () => {
   })
 
   afterEach(() => {
-    mock.clearAllMocks();
+    // Don't clear mocks - let them persist for other test files
+    // Navigation relies on module mocks set up at file level
   })
 
   it('renders the logo and basic links when not logged in', () => {