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/PtoResourceTest.php

@@ -0,0 +1,56 @@
+<?php
+
+use App\Http\Resources\PtoResource;
+use App\Models\Pto;
+use App\Models\Role;
+use App\Models\TeamMember;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Illuminate\Http\Request;
+use Tests\TestCase;
+
+uses(TestCase::class, RefreshDatabase::class);
+
+test('pto resource returns wrapped data with team member', function () {
+    $role = Role::factory()->create();
+    $teamMember = TeamMember::factory()->create(['role_id' => $role->id]);
+
+    $pto = Pto::create([
+        'team_member_id' => $teamMember->id,
+        'start_date' => '2026-02-10',
+        'end_date' => '2026-02-12',
+        'reason' => 'Travel',
+        'status' => 'pending',
+    ]);
+    $pto->load('teamMember');
+
+    $response = (new PtoResource($pto))->toResponse(Request::create('/'));
+    $payload = $response->getData(true);
+
+    expect($payload['data']['team_member_id'])->toBe($teamMember->id);
+    expect($payload['data']['team_member']['id'])->toBe($teamMember->id);
+});
+
+test('pto resource collection keeps data wrapper', function () {
+    $role = Role::factory()->create();
+    $member = TeamMember::factory()->create(['role_id' => $role->id]);
+
+    Pto::create([
+        'team_member_id' => $member->id,
+        'start_date' => '2026-02-10',
+        'end_date' => '2026-02-10',
+        'reason' => 'Travel',
+        'status' => 'approved',
+    ]);
+    Pto::create([
+        'team_member_id' => $member->id,
+        'start_date' => '2026-03-10',
+        'end_date' => '2026-03-12',
+        'reason' => 'Rest',
+        'status' => 'approved',
+    ]);
+
+    $response = PtoResource::collection(Pto::limit(2)->get())->toResponse(Request::create('/'));
+    $payload = $response->getData(true);
+
+    expect($payload['data'])->toHaveCount(2);
+});