feat(F-186): completed feature

work/artifacts/F-186/reviewer.json

@@ -0,0 +1,21 @@
+{
+  "feature_id": "F-186",
+  "agent": "reviewer",
+  "stage": "review_gate",
+  "verdict": "APPROVED",
+  "checks": [
+    { "item": "Eight-slot quick product and terminal discount contracts agree across admin, API and POS", "ok": true },
+    { "item": "Payment allocation requires an enabled method and exact authoritative total", "ok": true },
+    { "item": "Cash change and expected cash use tendered/applied values correctly", "ok": true },
+    { "item": "Sale, stock, reporting lines, payment rows and receipt sequence are atomic and idempotent", "ok": true },
+    { "item": "Free items are DB-constrained and excluded from inventory mutation", "ok": true },
+    { "item": "Receipt delivery precedes cashier reset", "ok": true },
+    { "item": "Unit, integration, migration, typecheck and production builds pass", "ok": true }
+  ],
+  "issues": [],
+  "notes": [
+    "Browser print APIs cannot distinguish a confirmed print from a cancelled print dialog; reset occurs when the print dialog returns.",
+    "Pending-payment orders and return tickets are intentionally tracked in F-188/F-189, not mixed into this fully-paid checkout contract.",
+    "Repository-wide lint debt outside changed files remains; targeted changed-file lint is green."
+  ]
+}