Add LOT API v1 endpoint with full batch details

Route changed to /api/v1/{lot_number}. LotResource now includes
packing details, units_produced, quantity_g and recipe version.
CORS config added for public API access. README documents the
endpoint, example response and subdomain setup instructions.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/Http/Controllers/Api/LotController.php

@@ -13,6 +13,7 @@ class LotController extends Controller
     {
         $batch = Batch::with([
             'product',
+            'size.packing',
             'recipe.spices',
             'origins.spice',
             'origins.supplier',