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/models.py

@@ -50,9 +50,18 @@ class PantryItem(models.Model):
         FREEZER = "freezer", "Freezer"
         CUPBOARD = "cupboard", "Cupboard"
 
+    class State(models.TextChoices):
+        IN = "in", "In stock"
+        LOW = "low", "Running low"
+        OUT = "out", "Out"
+
     ingredient = models.ForeignKey(Ingredient, on_delete=models.CASCADE)
-    quantity = models.DecimalField(max_digits=8, decimal_places=2)
-    unit = models.CharField(max_length=20)
+    # In/Low/Out is the primary signal. quantity is an optional rough count.
+    state = models.CharField(max_length=10, choices=State.choices, default=State.IN)
+    quantity = models.PositiveIntegerField(
+        null=True, blank=True, help_text="Optional rough count; In/Low/Out is the primary signal"
+    )
+    unit = models.CharField(max_length=20, blank=True)
     location = models.CharField(max_length=20, choices=Location.choices)
     stored_date = models.DateField(auto_now_add=True)
     expiry_date = models.DateField(null=True, blank=True)
@@ -65,7 +74,8 @@ class PantryItem(models.Model):
         ordering = ["expiry_date", "ingredient__name"]
 
     def __str__(self):
-        return f"{self.ingredient.name} ({self.quantity} {self.unit}) [{self.location}]"
+        qty = f"{self.quantity} {self.unit}" if self.quantity is not None else self.get_state_display()
+        return f"{self.ingredient.name} ({qty}) [{self.location}]"
 
     def clean(self):
         """Business rules for pantry items."""