fix: improve TypeScript types for better IDE code hinting

- Install @types/bun and @types/jsdom for proper type definitions
- Fix mock function typing in test files
- Create jest-dom.d.ts to properly extend Bun's Matchers interface
- Remove MockedFunction imports (not supported in Bun's types)
- Cast global.fetch and useSession mocks to any where needed
- Fix mock.module return types to match expected signatures

This resolves TypeScript errors that were preventing proper code
completion and type checking in IDEs.

src/__tests__/EditTournamentForm.test.tsx

@@ -1,4 +1,4 @@
-import { describe, it, expect, mock, beforeEach, MockedFunction } from 'bun:test'
+import { describe, it, expect, mock, beforeEach } from 'bun:test'
 import { render, screen, waitFor } from '@testing-library/react'
 import userEvent from '@testing-library/user-event'
 import EditTournamentForm from '@/components/EditTournamentForm'
@@ -18,8 +18,8 @@ mock.module('next/link', () => ({
 }))
 
 // Mock fetch
-const mockFetch = mock(() => {})
-global.fetch = mockFetch as MockedFunction<typeof global.fetch>
+const mockFetch = mock(async () => new Response())
+global.fetch = mockFetch as any
 
 const mockTournament = {
   id: 1,

src/__tests__/Navigation.test.tsx

@@ -18,7 +18,7 @@ mock.module('next/link', () => ({
 
 // Mock the SessionProvider
 mock.module('@/components/SessionProvider', () => ({
-  useSession: mock(() => {}),
+  useSession: mock(() => ({ session: null, loading: false, refreshSession: mock(() => {}) })),
 }))
 
 // Mock the auth-client
@@ -29,9 +29,10 @@ mock.module('@/lib/auth-client', () => ({
 }))
 
 // Mock fetch for role API call
-global.fetch = mock(() => {})
+global.fetch = mock(async () => new Response()) as any
 
-import { useSession } from '@/components/SessionProvider'
+import { useSession as useSessionOriginal } from '@/components/SessionProvider'
+const useSession = useSessionOriginal as any
 
 describe('Epic 1: Navigation Component', () => {
   beforeEach(() => {
@@ -131,7 +132,7 @@ describe('Epic 1: Navigation Component', () => {
     });
 
     // Mock fetch to return club_admin role
-    (global.fetch).mockImplementation(async (url) => {
+    (global.fetch as any).mockImplementation(async (url: any) => {
       if (url?.toString().includes('/api/users/admin-123/role')) {
         return new Response(JSON.stringify({ role: 'club_admin' }), {
           status: 200,
@@ -165,7 +166,7 @@ describe('Epic 1: Navigation Component', () => {
     });
 
     // Mock fetch to return player role (already set in beforeEach, but explicit here)
-    (global.fetch).mockImplementation(async (url) => {
+    (global.fetch as any).mockImplementation(async (url: any) => {
       if (url?.toString().includes('/api/users/')) {
         return {
           json: () => Promise.resolve({ role: 'player' }),

src/__tests__/auth-simple.test.ts

@@ -1,19 +1,19 @@
-import { describe, it, expect, mock, beforeEach, MockedFunction } from 'bun:test'
+import { describe, it, expect, mock, beforeEach } from 'bun:test'
 import { getSession } from '@/lib/auth-simple'
 
 // Mock next/headers
 mock.module('next/headers', () => ({
-  cookies: mock(() => {}).mockResolvedValue({
-    get: mock(() => {}).mockReturnValue({ name: 'better-auth.session_token', value: 'test-token' }),
-  }),
-  headers: mock(() => {}).mockResolvedValue({
-    get: mock(() => {}).mockReturnValue(null),
-  }),
+  cookies: mock(() => Promise.resolve({
+    get: mock(() => ({ name: 'better-auth.session_token', value: 'test-token' })),
+  })),
+  headers: mock(() => Promise.resolve({
+    get: mock(() => null),
+  })),
 }))
 
 // Mock fetch
-const mockFetch = mock(() => {})
-global.fetch = mockFetch as MockedFunction<typeof global.fetch>
+const mockFetch = mock(async () => new Response())
+global.fetch = mockFetch as any
 
 describe('getSession', () => {
   beforeEach(() => {

src/__tests__/jest-dom.d.ts

@@ -0,0 +1,12 @@
+/// <reference types="@testing-library/jest-dom" />
+
+import { type expect } from 'bun:test'
+import { type TestingLibraryMatchers } from '@testing-library/jest-dom/matchers'
+
+declare module 'bun:test' {
+  interface Matchers<T = any>
+    extends TestingLibraryMatchers<
+      ReturnType<typeof expect.stringContaining>,
+      T
+    > {}
+}