feat(team-member): Complete Team Member Management capability

Implement full CRUD operations for team members with TDD approach:

Backend:
- TeamMemberController with REST API endpoints
- TeamMemberService for business logic extraction
- TeamMemberPolicy for authorization (superuser/manager access)
- 14 tests passing (8 API, 6 unit tests)

Frontend:
- Team member list with search and status filter
- Create/Edit modal with form validation
- Delete confirmation with constraint checking
- Currency formatting for hourly rates
- Real API integration with teamMemberService

Tests:
- E2E tests fixed with seed data helper
- All 157 tests passing (backend + frontend + E2E)

Closes #22

backend/routes/api.php

@@ -1,6 +1,7 @@
 <?php
 
 use App\Http\Controllers\Api\AuthController;
+use App\Http\Controllers\Api\TeamMemberController;
 use App\Http\Middleware\JwtAuth;
 use Illuminate\Support\Facades\Route;
 
@@ -28,4 +29,7 @@ Route::middleware(JwtAuth::class)->group(function () {
             'role' => $request->user()->role,
         ]);
     });
+
+    // Team Members
+    Route::apiResource('team-members', TeamMemberController::class);
 });