security: A01-13 — nest all event routes under organisation prefix

Move all authenticated organiser-facing event sub-resource routes from
/events/{event}/... to /organisations/{organisation}/events/{event}/...
to enforce multi-tenancy at the routing layer.

Changes:
- Routes: restructured api.php to nest all event sub-resources under
  the existing organisation prefix group
- Controllers: added Organisation parameter and VerifiesOrganisationEvent
  trait to all 12 affected controllers (sections, time-slots, shifts,
  persons, crowd-lists, locations, shift-assignments, registration-fields,
  availabilities, field-values, section-preferences, stats)
- Tests: updated all 20 feature test files with new route paths
- Frontend: updated 8 API composables and 20 Vue components/pages
- API.md: updated documentation to reflect new route structure

Portal routes, public routes (volunteer-register), and invitation routes
remain unchanged as they operate without organisation context.

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

api/app/Http/Controllers/Api/V1/FestivalSectionController.php

@@ -5,6 +5,7 @@ declare(strict_types=1);
 namespace App\Http\Controllers\Api\V1;
 
 use App\Http\Controllers\Controller;
+use App\Http\Controllers\Api\V1\Traits\VerifiesOrganisationEvent;
 use App\Http\Requests\Api\V1\ReorderFestivalSectionsRequest;
 use App\Http\Requests\Api\V1\StoreFestivalSectionRequest;
 use App\Http\Requests\Api\V1\UpdateFestivalSectionRequest;
@@ -12,14 +13,18 @@ use App\Http\Requests\Api\V1\UpdateRegistrationSettingsRequest;
 use App\Http\Resources\Api\V1\FestivalSectionResource;
 use App\Models\Event;
 use App\Models\FestivalSection;
+use App\Models\Organisation;
 use Illuminate\Http\JsonResponse;
 use Illuminate\Http\Resources\Json\AnonymousResourceCollection;
 use Illuminate\Support\Facades\Gate;
 
 final class FestivalSectionController extends Controller
 {
-    public function index(Event $event): AnonymousResourceCollection
+    use VerifiesOrganisationEvent;
+
+    public function index(Organisation $organisation, Event $event): AnonymousResourceCollection
     {
+        $this->verifyEventBelongsToOrganisation($organisation, $event);
         Gate::authorize('viewAny', [FestivalSection::class, $event]);
 
         $sections = $event->festivalSections()->ordered()->get();
@@ -38,8 +43,9 @@ final class FestivalSectionController extends Controller
         return FestivalSectionResource::collection($sections);
     }
 
-    public function store(StoreFestivalSectionRequest $request, Event $event): JsonResponse
+    public function store(StoreFestivalSectionRequest $request, Organisation $organisation, Event $event): JsonResponse
     {
+        $this->verifyEventBelongsToOrganisation($organisation, $event);
         Gate::authorize('create', [FestivalSection::class, $event]);
 
         $data = $request->validated();
@@ -77,8 +83,9 @@ final class FestivalSectionController extends Controller
         return $response;
     }
 
-    public function update(UpdateFestivalSectionRequest $request, Event $event, FestivalSection $section): JsonResponse
+    public function update(UpdateFestivalSectionRequest $request, Organisation $organisation, Event $event, FestivalSection $section): JsonResponse
     {
+        $this->verifyEventBelongsToOrganisation($organisation, $event);
         Gate::authorize('update', [$section, $event]);
 
         $section->update($request->validated());
@@ -86,8 +93,9 @@ final class FestivalSectionController extends Controller
         return $this->success(new FestivalSectionResource($section->fresh()));
     }
 
-    public function destroy(Event $event, FestivalSection $section): JsonResponse
+    public function destroy(Organisation $organisation, Event $event, FestivalSection $section): JsonResponse
     {
+        $this->verifyEventBelongsToOrganisation($organisation, $event);
         Gate::authorize('delete', [$section, $event]);
 
         $section->delete();
@@ -95,8 +103,9 @@ final class FestivalSectionController extends Controller
         return response()->json(null, 204);
     }
 
-    public function registrationSettings(Event $event): JsonResponse
+    public function registrationSettings(Organisation $organisation, Event $event): JsonResponse
     {
+        $this->verifyEventBelongsToOrganisation($organisation, $event);
         Gate::authorize('viewAny', [FestivalSection::class, $event]);
 
         $sections = $this->getFestivalSections($event);
@@ -118,8 +127,9 @@ final class FestivalSectionController extends Controller
         return response()->json(['data' => $grouped]);
     }
 
-    public function updateRegistrationSettings(UpdateRegistrationSettingsRequest $request, Event $event): JsonResponse
+    public function updateRegistrationSettings(UpdateRegistrationSettingsRequest $request, Organisation $organisation, Event $event): JsonResponse
     {
+        $this->verifyEventBelongsToOrganisation($organisation, $event);
         Gate::authorize('create', [FestivalSection::class, $event]);
 
         $validated = $request->validated();
@@ -148,7 +158,7 @@ final class FestivalSectionController extends Controller
             ->log('section.registration_settings_updated');
 
         // Return updated settings
-        return $this->registrationSettings($event);
+        return $this->registrationSettings($organisation, $event);
     }
 
     /**
@@ -171,8 +181,9 @@ final class FestivalSectionController extends Controller
         return FestivalSection::whereIn('event_id', $eventIds)->ordered()->get();
     }
 
-    public function reorder(ReorderFestivalSectionsRequest $request, Event $event): JsonResponse
+    public function reorder(ReorderFestivalSectionsRequest $request, Organisation $organisation, Event $event): JsonResponse
     {
+        $this->verifyEventBelongsToOrganisation($organisation, $event);
         Gate::authorize('reorder', [FestivalSection::class, $event]);
 
         foreach ($request->validated('sections') as $index => $id) {