Allow recording zero eggs collected

Enable recording "checked coop, found 0 eggs" to distinguish from days
when the coop wasn't checked at all. Statistics remain eggs/calendar day.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/animaltrack/events/payloads.py

@@ -308,7 +308,7 @@ class ProductCollectedPayload(BaseModel):
 
     location_id: str = Field(..., min_length=26, max_length=26)
     product_code: str
-    quantity: int = Field(..., ge=1)
+    quantity: int = Field(..., ge=0)  # 0 allowed: checked but found none
     resolved_ids: list[str] = Field(..., min_length=1)
     notes: str | None = None
 

src/animaltrack/web/routes/eggs.py

@@ -376,9 +376,9 @@ async def product_collected(request: Request, session):
             request, db, locations, products, location_id, "Quantity must be a number"
         )
 
-    if quantity < 1:
+    if quantity < 0:
         return _render_harvest_error(
-            request, db, locations, products, location_id, "Quantity must be at least 1"
+            request, db, locations, products, location_id, "Quantity cannot be negative"
         )
 
     # Get timestamp - use provided or current (supports backdating)

src/animaltrack/web/templates/eggs.py

@@ -184,13 +184,13 @@ def harvest_form(
             id="location_id",
             name="location_id",
         ),
-        # Quantity input (integer only, min=1)
+        # Quantity input (integer only, 0 allowed for "checked but found none")
         LabelInput(
             "Quantity",
             id="quantity",
             name="quantity",
             type="number",
-            min="1",
+            min="0",
             step="1",
             placeholder="Number of eggs",
             required=True,

tests/test_event_payloads.py

@@ -285,15 +285,27 @@ class TestProductPayloads:
         )
         assert payload.quantity == 12
 
-    def test_quantity_must_be_positive(self):
+    def test_quantity_zero_is_valid(self):
-        """quantity must be >= 1."""
+        """quantity=0 is valid (checked but found none)."""
+        from animaltrack.events.payloads import ProductCollectedPayload
+
+        payload = ProductCollectedPayload(
+            location_id="01ARZ3NDEKTSV4RRFFQ69G5FAV",
+            product_code="egg.duck",
+            quantity=0,
+            resolved_ids=["01ARZ3NDEKTSV4RRFFQ69G5FAV"],
+        )
+        assert payload.quantity == 0
+
+    def test_quantity_cannot_be_negative(self):
+        """quantity must be >= 0."""
         from animaltrack.events.payloads import ProductCollectedPayload
 
         with pytest.raises(ValidationError):
             ProductCollectedPayload(
                 location_id="01ARZ3NDEKTSV4RRFFQ69G5FAV",
                 product_code="egg.duck",
-                quantity=0,
+                quantity=-1,
                 resolved_ids=["01ARZ3NDEKTSV4RRFFQ69G5FAV"],
             )
 

tests/test_web_eggs.py

@@ -137,10 +137,10 @@ class TestEggCollection:
         assert event_row is not None
         assert event_row[0] == "ProductCollected"
 
-    def test_egg_collection_validation_quantity_zero(
+    def test_egg_collection_quantity_zero_accepted(
-        self, client, location_strip1_id, ducks_at_strip1
+        self, client, seeded_db, location_strip1_id, ducks_at_strip1
     ):
-        """quantity=0 returns 422."""
+        """quantity=0 is accepted (checked coop, found no eggs)."""
         resp = client.post(
             "/actions/product-collected",
             data={
@@ -150,7 +150,17 @@ class TestEggCollection:
             },
         )
 
-        assert resp.status_code == 422
+        assert resp.status_code in [200, 302, 303]
+
+        # Verify event was created with quantity=0
+        event_row = seeded_db.execute(
+            "SELECT payload FROM events WHERE type = 'ProductCollected' ORDER BY id DESC LIMIT 1"
+        ).fetchone()
+        assert event_row is not None
+        import json
+
+        payload = json.loads(event_row[0])
+        assert payload["quantity"] == 0
 
     def test_egg_collection_validation_quantity_negative(
         self, client, location_strip1_id, ducks_at_strip1