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/app/Policies/TeamMemberPolicy.php

@@ -0,0 +1,72 @@
+<?php
+
+namespace App\Policies;
+
+use App\Models\TeamMember;
+use App\Models\User;
+
+class TeamMemberPolicy
+{
+    /**
+     * Determine whether the user can view any models.
+     */
+    public function viewAny(User $user): bool
+    {
+        // All authenticated users can view team members
+        return true;
+    }
+
+    /**
+     * Determine whether the user can view the model.
+     */
+    public function view(User $user, TeamMember $teamMember): bool
+    {
+        // All authenticated users can view individual team members
+        return true;
+    }
+
+    /**
+     * Determine whether the user can create models.
+     */
+    public function create(User $user): bool
+    {
+        // Only superusers and managers can create team members
+        return in_array($user->role, ['superuser', 'manager']);
+    }
+
+    /**
+     * Determine whether the user can update the model.
+     */
+    public function update(User $user, TeamMember $teamMember): bool
+    {
+        // Only superusers and managers can update team members
+        return in_array($user->role, ['superuser', 'manager']);
+    }
+
+    /**
+     * Determine whether the user can delete the model.
+     */
+    public function delete(User $user, TeamMember $teamMember): bool
+    {
+        // Only superusers and managers can delete team members
+        return in_array($user->role, ['superuser', 'manager']);
+    }
+
+    /**
+     * Determine whether the user can restore the model.
+     */
+    public function restore(User $user, TeamMember $teamMember): bool
+    {
+        // Only superusers and managers can restore team members
+        return in_array($user->role, ['superuser', 'manager']);
+    }
+
+    /**
+     * Determine whether the user can permanently delete the model.
+     */
+    public function forceDelete(User $user, TeamMember $teamMember): bool
+    {
+        // Only superusers can force delete team members
+        return $user->role === 'superuser';
+    }
+}