feat: surface pantry-expiry recipe suggestions

Pantry page now shows a "Use it up soon" widget with recipes that use
soon-to-expire pantry items, across the user's own recipes plus public/
unlisted ones (the existing /recipes/can-cook page only looked at the
user's own). Extracted the matching/scoring logic shared by both into
lib/pantry-match.ts.

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

apps/web/messages/fr.json

@@ -610,6 +610,8 @@
     "title": "Garde-manger",
     "subtitle": "Suivez ce que vous avez en stock",
     "canCook": "Que puis-je cuisiner ?",
+    "expiringSoonSuggestionsTitle": "À utiliser bientôt",
+    "seeAll": "Tout voir",
     "itemNamePlaceholder": "Nom de l'article",
     "qtyPlaceholder": "Qté",
     "unitPlaceholder": "Unité",