feat(api): Implement API Resource Standard compliance

- Create BaseResource with formatDate() and formatDecimal() utilities
- Create 11 API Resource classes for all models
- Update all 6 controllers to return wrapped responses via wrapResource()
- Update frontend API client with unwrapResponse() helper
- Update all 63+ backend tests to expect 'data' wrapper
- Regenerate Scribe API documentation

BREAKING CHANGE: All API responses now wrap data in 'data' key per architecture spec.

Backend Tests: 70 passed, 5 failed (unrelated to data wrapper)
Frontend Unit: 10 passed
E2E Tests: 102 passed, 20 skipped
API Docs: Generated successfully

Refs: openspec/changes/api-resource-standard

backend/tests/Unit/Resources/UserResourceTest.php

@@ -0,0 +1,30 @@
+<?php
+
+use App\Http\Resources\UserResource;
+use App\Models\User;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Illuminate\Http\Request;
+use Tests\TestCase;
+
+uses(TestCase::class, RefreshDatabase::class);
+
+test('user resource wraps response with data', function () {
+    $user = User::factory()->create();
+
+    $response = (new UserResource($user))->toResponse(Request::create('/'));
+    $payload = $response->getData(true);
+
+    expect(array_key_exists('data', $payload))->toBeTrue();
+    expect($payload['data']['id'])->toBe($user->id);
+    expect($payload['data'])->toHaveKey('email');
+});
+
+test('user resource collection honors data wrapper', function () {
+    $users = User::factory()->count(2)->create();
+
+    $response = UserResource::collection($users)->toResponse(Request::create('/'));
+    $payload = $response->getData(true);
+
+    expect($payload['data'])->toHaveCount(2);
+    expect($payload['data'][0])->toHaveKey('id');
+});