feat(pos-selfpay-flow): pOS selfpay: simplified pay flow with optional email receipt

backlog/features.json

@@ -8002,14 +8002,16 @@
       "description": "In selfpay mode show only 'Pagar' and 'Limpiar ticket'. On pay, ask optional email, then show payment methods. Cash prints the ticket and sends customer to cashier; if email was provided, also send the receipt by email. Keep card/other methods ready for future posnet integration.",
       "priority": "high",
       "risk": "high",
-      "status": "pending",
+      "status": "done",
       "created_at": "2026-08-26",
       "gates": {
-        "reviewer": false,
-        "security": false,
-        "qa": false
+        "reviewer": true,
+        "security": true,
+        "qa": true,
+        "close": true
       },
-      "phase": "pos"
+      "phase": "pos",
+      "completed_at": "2026-08-26T18:40:43Z"
     },
     {
       "id": "CLUB-001",