fix: extend source CHECK constraints to include visual_capture (kiwi#79)

Migrations 037 and 038 rebuild products and inventory_items tables
to add 'visual_capture' as a valid source value, which the label-confirm
endpoint sets when saving user-verified nutrition label data.
Adds 2 schema tests covering the new allowed value.

app/db/migrations/037_products_source_visual_capture.sql

@@ -0,0 +1,34 @@
+-- Migration 037: add 'visual_capture' to products.source CHECK constraint
+-- SQLite cannot ALTER a CHECK constraint, so we rebuild the table.
+
+PRAGMA foreign_keys = OFF;
+
+BEGIN;
+
+CREATE TABLE products_new (
+    id              INTEGER PRIMARY KEY AUTOINCREMENT,
+    barcode         TEXT UNIQUE,
+    name            TEXT NOT NULL,
+    brand           TEXT,
+    category        TEXT,
+    description     TEXT,
+    image_url       TEXT,
+    nutrition_data  TEXT NOT NULL DEFAULT '{}',
+    source          TEXT NOT NULL DEFAULT 'openfoodfacts'
+                         CHECK (source IN ('openfoodfacts', 'manual', 'receipt_ocr', 'visual_capture')),
+    source_data     TEXT,
+    created_at      TEXT NOT NULL DEFAULT (datetime('now')),
+    updated_at      TEXT NOT NULL DEFAULT (datetime('now'))
+);
+
+INSERT INTO products_new
+    SELECT id, barcode, name, brand, category, description, image_url,
+           nutrition_data, source, source_data, created_at, updated_at
+    FROM products;
+
+DROP TABLE products;
+ALTER TABLE products_new RENAME TO products;
+
+COMMIT;
+
+PRAGMA foreign_keys = ON;

app/db/migrations/038_inventory_items_source_visual_capture.sql

@@ -0,0 +1,43 @@
+-- Migration 038: add 'visual_capture' to inventory_items.source CHECK constraint
+-- SQLite cannot ALTER a CHECK constraint, so we rebuild the table.
+
+PRAGMA foreign_keys = OFF;
+
+BEGIN;
+
+CREATE TABLE inventory_items_new (
+    id              INTEGER PRIMARY KEY AUTOINCREMENT,
+    product_id      INTEGER NOT NULL
+                        REFERENCES products (id) ON DELETE RESTRICT,
+    receipt_id      INTEGER
+                        REFERENCES receipts (id) ON DELETE SET NULL,
+    quantity        REAL NOT NULL DEFAULT 1 CHECK (quantity > 0),
+    unit            TEXT NOT NULL DEFAULT 'count',
+    location        TEXT NOT NULL,
+    sublocation     TEXT,
+    purchase_date   TEXT,
+    expiration_date TEXT,
+    status          TEXT NOT NULL DEFAULT 'available'
+                        CHECK (status IN ('available', 'consumed', 'expired', 'discarded')),
+    consumed_at     TEXT,
+    notes           TEXT,
+    source          TEXT NOT NULL DEFAULT 'manual'
+                        CHECK (source IN ('barcode_scan', 'manual', 'receipt', 'visual_capture')),
+    created_at      TEXT NOT NULL DEFAULT (datetime('now')),
+    updated_at      TEXT NOT NULL DEFAULT (datetime('now')),
+    opened_date     TEXT,
+    disposal_reason TEXT
+);
+
+INSERT INTO inventory_items_new
+    SELECT id, product_id, receipt_id, quantity, unit, location, sublocation,
+           purchase_date, expiration_date, status, consumed_at, notes, source,
+           created_at, updated_at, opened_date, disposal_reason
+    FROM inventory_items;
+
+DROP TABLE inventory_items;
+ALTER TABLE inventory_items_new RENAME TO inventory_items;
+
+COMMIT;
+
+PRAGMA foreign_keys = ON;

tests/db/test_captured_products.py

@@ -11,6 +11,42 @@ def store(tmp_path: Path) -> Store:
     s.close()
 
 
+class TestProductsSchema:
+    """Verify migrations 037/038 allow 'visual_capture' as a valid source."""
+
+    def test_products_accepts_visual_capture_source(self, store):
+        """Migration 037: products.source CHECK includes 'visual_capture'."""
+        store.conn.execute(
+            "INSERT INTO products (name, source) VALUES (?, ?)",
+            ("Test Product", "visual_capture"),
+        )
+        store.conn.commit()
+        row = store.conn.execute(
+            "SELECT source FROM products WHERE name='Test Product'"
+        ).fetchone()
+        assert row[0] == "visual_capture"
+
+    def test_inventory_items_accepts_visual_capture_source(self, store):
+        """Migration 038: inventory_items.source CHECK includes 'visual_capture'."""
+        store.conn.execute(
+            "INSERT INTO products (name, source) VALUES (?, ?)",
+            ("Temp Product", "manual"),
+        )
+        store.conn.commit()
+        product_id = store.conn.execute(
+            "SELECT id FROM products WHERE name='Temp Product'"
+        ).fetchone()[0]
+        store.conn.execute(
+            "INSERT INTO inventory_items (product_id, location, source) VALUES (?, ?, ?)",
+            (product_id, "pantry", "visual_capture"),
+        )
+        store.conn.commit()
+        row = store.conn.execute(
+            "SELECT source FROM inventory_items WHERE product_id=?", (product_id,)
+        ).fetchone()
+        assert row[0] == "visual_capture"
+
+
 class TestMigration:
     def test_captured_products_table_exists(self, store):
         cur = store.conn.execute(