Phase 1: mobile-first pantry redesign with In/Low/Out state

Track presence (In/Low/Out) as the primary signal instead of exact
quantities; quantity becomes an optional integer, unit optional too
(migration 0003 backfills state from quantity: 0 -> out, else in).

- Pantry rebuilt as a phone-first card list: colored state rail,
  segmented In/Low/Out switch (server-driven HTMX), greyed out-items,
  live summary counts.
- Fast add: bottom add bar with type-ahead autocomplete, location
  picker, and quick-add chips for things you've run out of.
- Per-item menu (move / set expiry / delete); expiry is now an
  optional quiet pill, never required.
- New endpoints: pantry search + set-state; dropped the old
  edit-expiry/cancel flow and its partial.
- Recipes matcher made presence-based (have-it beats have-enough);
  state added to admin. Tests cover state, add/restock, search,
  presence matching, and page rendering.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

kitchen/helpers.py

@@ -25,10 +25,15 @@ def find_ingredient(name):
 
 
 def get_pantry_total(ingredient_id):
-    """Get total quantity of an ingredient across all pantry locations."""
+    """Total quantity of an ingredient across all locations, excluding items
+    marked 'out'. Null quantities count as 0 (presence is tracked via state,
+    not this number — see the pantry redesign in plan.md)."""
     total = Decimal("0")
-    for item in PantryItem.objects.filter(ingredient_id=ingredient_id, quantity__gt=0):
-        total += item.quantity
+    for item in (
+        PantryItem.objects.filter(ingredient_id=ingredient_id)
+        .exclude(state=PantryItem.State.OUT)
+    ):
+        total += Decimal(item.quantity or 0)
     return total