feat(purchase): implement PurchaseController with CRUD operations and request validation

app/Domains/Purchase/routes/api.php

@@ -0,0 +1,8 @@
+<?php
+
+use App\Domains\Purchase\Controllers\PurchaseController;
+use Illuminate\Support\Facades\Route;
+
+Route::prefix('tenants/{tenant:codigo}')->middleware('auth:sanctum')->group(function (): void {
+    Route::apiResource('compras', PurchaseController::class)->only(['index', 'store', 'show']);
+});