fix: smart shopping family suppression, shelf life pre-warming (v1.7.7)

- Remove recentlyExhausted bypass from shopping_name family suppression:
  products recently exhausted (<14d) were incorrectly flagged as critical
  even when the same family had ample stock (Yogurt 2002g, Affettato 1022g,
  Pane 400g). recentlyExhausted now only bypasses loose token-based coverage.
- Add prewarmShelfLifeCache() in cron: pre-warms opened shelf life via
  Gemini AI (max 5 items/cycle) so the UI never blocks on first load.

manifest.json

@@ -2,7 +2,7 @@
     "name": "EverShelf",
     "short_name": "EverShelf",
     "description": "Gestione completa della dispensa di casa con scansione barcode",
-    "version": "1.7.6",
+    "version": "1.7.7",
     "start_url": "/evershelf/",
     "display": "standalone",
     "background_color": "#f0f4e8",