feat: platform admin member management — invite, remove, role update

Add member management to the platform admin organisation detail page:
- Backend: invite (creates invitation or directly adds existing user),
  remove member, update member role endpoints on AdminOrganisationController
- Backend: show endpoint now returns members alongside organisation data
- Frontend: members table with inline role editing, invite dialog,
  remove confirmation dialog on /platform/organisations/[id]
- Tests: 7 new tests covering happy paths and edge cases (self-removal,
  existing member, non-super_admin denied)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

api/app/Http/Controllers/Api/V1/Admin/AdminOrganisationController.php

@@ -5,10 +5,15 @@ declare(strict_types=1);
 namespace App\Http\Controllers\Api\V1\Admin;
 
 use App\Http\Controllers\Controller;
+use App\Http\Requests\Admin\AdminInviteMemberRequest;
+use App\Http\Requests\Admin\AdminUpdateMemberRoleRequest;
 use App\Http\Requests\Admin\AdminUpdateOrganisationRequest;
 use App\Http\Resources\Admin\AdminOrganisationResource;
+use App\Http\Resources\Api\V1\MemberResource;
 use App\Models\Organisation;
 use App\Models\Person;
+use App\Models\User;
+use App\Models\UserInvitation;
 use Illuminate\Http\JsonResponse;
 use Illuminate\Http\Resources\Json\AnonymousResourceCollection;
 
@@ -50,7 +55,12 @@ final class AdminOrganisationController extends Controller
             ->whereIn('event_id', $organisation->events()->select('id'))
             ->count();
 
-        return $this->success(new AdminOrganisationResource($organisation));
+        $members = $organisation->users()->orderBy('first_name')->get();
+
+        return $this->success([
+            'organisation' => new AdminOrganisationResource($organisation),
+            'members' => MemberResource::collection($members),
+        ]);
     }
 
     public function store(): void
@@ -91,4 +101,104 @@ final class AdminOrganisationController extends Controller
 
         return response()->json(null, 204);
     }
+
+    public function invite(AdminInviteMemberRequest $request, string $organisationId): JsonResponse
+    {
+        $organisation = Organisation::withoutGlobalScopes()->findOrFail($organisationId);
+        $email = $request->validated('email');
+        $role = $request->validated('role');
+
+        // Check if already a member
+        $existingMember = $organisation->users()->where('email', $email)->first();
+
+        if ($existingMember) {
+            return $this->error('Gebruiker is al lid van deze organisatie.', 422);
+        }
+
+        // If user with this email already exists, add directly
+        $existingUser = User::where('email', $email)->first();
+
+        if ($existingUser) {
+            $organisation->users()->attach($existingUser, ['role' => $role]);
+
+            activity('admin')
+                ->causedBy(auth()->user())
+                ->performedOn($organisation)
+                ->event('admin.organisation.member_invited')
+                ->withProperties(['email' => $email, 'role' => $role, 'direct' => true])
+                ->log("Added existing user {$email} as {$role}");
+
+            return $this->success(
+                new MemberResource($organisation->users()->where('user_id', $existingUser->id)->first()),
+                'Gebruiker direct toegevoegd als lid.',
+            );
+        }
+
+        // Create invitation for unknown email
+        $invitation = new UserInvitation(['email' => $email]);
+        $invitation->invited_by_user_id = auth()->id();
+        $invitation->organisation_id = $organisation->id;
+        $invitation->role = $role;
+        $invitation->token = hash('sha256', bin2hex(random_bytes(32)));
+        $invitation->status = 'pending';
+        $invitation->expires_at = now()->addDays(7);
+        $invitation->save();
+
+        activity('admin')
+            ->causedBy(auth()->user())
+            ->performedOn($organisation)
+            ->event('admin.organisation.member_invited')
+            ->withProperties(['email' => $email, 'role' => $role, 'direct' => false])
+            ->log("Invited {$email} as {$role}");
+
+        return $this->created(null, 'Uitnodiging aangemaakt.');
+    }
+
+    public function removeMember(string $organisationId, User $user): JsonResponse
+    {
+        $organisation = Organisation::withoutGlobalScopes()->findOrFail($organisationId);
+
+        if (auth()->id() === $user->id) {
+            return $this->error('Je kunt jezelf niet verwijderen.', 422);
+        }
+
+        if (!$organisation->users()->where('user_id', $user->id)->exists()) {
+            return $this->notFound('Gebruiker is geen lid van deze organisatie.');
+        }
+
+        $organisation->users()->detach($user->id);
+
+        activity('admin')
+            ->causedBy(auth()->user())
+            ->performedOn($organisation)
+            ->event('admin.organisation.member_removed')
+            ->withProperties(['user_id' => $user->id, 'email' => $user->email])
+            ->log("Removed {$user->email} from organisation");
+
+        return response()->json(null, 204);
+    }
+
+    public function updateMemberRole(AdminUpdateMemberRoleRequest $request, string $organisationId, User $user): JsonResponse
+    {
+        $organisation = Organisation::withoutGlobalScopes()->findOrFail($organisationId);
+
+        if (!$organisation->users()->where('user_id', $user->id)->exists()) {
+            return $this->notFound('Gebruiker is geen lid van deze organisatie.');
+        }
+
+        $organisation->users()->updateExistingPivot($user->id, [
+            'role' => $request->validated('role'),
+        ]);
+
+        activity('admin')
+            ->causedBy(auth()->user())
+            ->performedOn($organisation)
+            ->event('admin.organisation.member_role_updated')
+            ->withProperties(['user_id' => $user->id, 'role' => $request->validated('role')])
+            ->log("Updated role of {$user->email} to {$request->validated('role')}");
+
+        return $this->success(
+            new MemberResource($organisation->users()->where('user_id', $user->id)->first()),
+        );
+    }
 }