docs: add notification and concurrency test procedures

11 - Testing/Testing Expansion Backlog.md

@@ -102,6 +102,50 @@ Add Playwright tests for:
 - payment submitted screen waits for scanner confirmation;
 - paid socket/poll fallback transitions to success.
 
+## P1 - Notification Assertions
+
+Turn [[Notification Assertion Procedure]] into reusable E2E helpers:
+
+- capture per-user notification baseline;
+- poll `GET /api/notifications` and `GET /api/notifications/unread-count`;
+- optionally attach Socket.IO clients for buyer/seller/admin actors;
+- fail on wrong-recipient notifications;
+- record known notification gaps with route/action and expected recipient;
+- include notification latency in every E2E report.
+
+Acceptance tests:
+
+| ID | Expected |
+|---|---|
+| NOTIF-E2E-001 | New seller offer creates a buyer notification and unread-count increment. |
+| NOTIF-E2E-002 | Buyer offer acceptance creates selected seller notification. |
+| NOTIF-E2E-003 | Seller delivery creates buyer notification. |
+| NOTIF-E2E-004 | Buyer delivery confirmation creates seller notification. |
+| NOTIF-E2E-005 | Missing `pending_payment` notification is reported as a known gap, not a silent pass. |
+
+## P1 - Concurrency and Performance Profile
+
+Implement [[Concurrency and Performance Profile]] as an executable runner and
+report generator:
+
+- worker abstraction for one isolated buyer/sellers/payment/delivery flow;
+- barrier start for simultaneous workers;
+- ramp stages `1, 2, 4, 8, 16, 32`;
+- JSON result per worker;
+- markdown performance profile report per run;
+- infrastructure snapshots before/during/after each stage;
+- stop-condition enforcement.
+
+Acceptance tests:
+
+| ID | Expected |
+|---|---|
+| PERF-CONC-001 | C1 completes with all notification assertions. |
+| PERF-CONC-002 | C2/C4 detect no cross-worker state leakage. |
+| PERF-CONC-003 | Report includes p50/p95/p99 API, scanner, notification, and total timings. |
+| PERF-CONC-004 | Runner stops the ramp on P0 notification/payment/ledger correctness failure. |
+| PERF-CONC-005 | Runner separates live-chain mode from scanner-fixture/API-only modes. |
+
 ## P1 - CI and Deployment
 
 Add a deployment smoke checklist artifact after every pipeline:
@@ -142,4 +186,3 @@ Add dashboards/log queries for:
 5. Add release-policy tests.
 6. Resolve dispute route/policy gaps.
 7. Add dispute-to-release/refund E2E tests.
-