[IMP] website_sale_aplicoop: automate non-weekly group order cycles

One-time, biweekly and monthly group orders now follow the same cron
confirmation flow as weekly ones (confirm sale orders + batch pickings
when the cycle cutoff passes):

- Biweekly/monthly keep the cutoff_day/pickup_day weekday scheme on a
  recurrence grid anchored at start_date (creation date as fallback):
  cutoffs advance +14 days / +1 month snapped to cutoff_day, with
  catch-up after cron downtime. Previously they behaved as weekly.
- One-time orders (specials/promotions) are driven by end_date
  (cutoff_date = end_date); once passed, the cron confirms, batches
  and closes the group order.
- end_date keeps its "empty = permanent" meaning for recurring orders.
- Website draft-cart lookup window is now period-aware instead of
  assuming a 6-day weekly cycle.
- New cron tests for once/biweekly/monthly cycles; i18n es/eu updated.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

website_sale_aplicoop/__manifest__.py

@@ -3,7 +3,7 @@
 
 {  # noqa: B018
     "name": "Website Sale - Aplicoop",
-    "version": "18.0.1.10.2",
+    "version": "18.0.1.11.0",
     "category": "Website/Sale",
     "summary": "Modern replacement of legacy Aplicoop - Collaborative consumption group orders",
     "author": "Odoo Community Association (OCA), Criptomart",