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/ProjectResourceTest.php

@@ -0,0 +1,31 @@
+<?php
+
+use App\Http\Resources\ProjectResource;
+use App\Models\Project;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Illuminate\Http\Request;
+use Tests\TestCase;
+
+uses(TestCase::class, RefreshDatabase::class);
+
+test('project resource includes expected fields inside data wrapper', function () {
+    $project = Project::factory()->approved()->create();
+    $project->load(['status', 'type']);
+
+    $response = (new ProjectResource($project))->toResponse(Request::create('/'));
+    $payload = $response->getData(true);
+
+    expect($payload)->toHaveKey('data');
+    expect($payload['data'])->toHaveKey('status');
+    expect($payload['data'])->toHaveKey('type');
+    expect($payload['data'])->toHaveKey('approved_estimate');
+});
+
+test('project resource collection wraps multiple entries', function () {
+    $projects = Project::factory()->count(2)->create();
+
+    $response = ProjectResource::collection($projects)->toResponse(Request::create('/'));
+    $payload = $response->getData(true);
+
+    expect($payload['data'])->toHaveCount(2);
+});