Add AI-assisted QA test workflow: scenario cards, runner, hooks, API capture

A complete loop for defining, generating, running and gating tests:

- qa/: scenario-card template + examples (API/UI/binding), the Claude
  generation prompt, and a QA runbook tying it together
- e2e/CLAUDE.md: conventions that keep AI-generated tests consistent
- run-tests.ps1: one runner for every layer (backend/api/web/ui/binding),
  logs per run under .testlogs/, JUnit output, evidence report, and a
  re-seed guard against stale demo data
- .githooks/ + scripts/install-hooks.ps1: pre-commit secret scan and
  pre-push unit tests (shift-left before CI)
- evidence report now captures each API call's request, payload and
  response (Authorization redacted); JUnit reporter added for CI
- scripts/db.mjs: db:check freshness guard

Azure DevOps pipeline deferred; the runner already emits JUnit + the
evidence report for any CI to publish.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

qa/scenarios/BOOK-012-no-oversell.yml

@@ -0,0 +1,28 @@
+id: BOOK-012
+title: The last seat cannot be oversold to two agents at once
+layer: binding
+area: Booking and cancelling
+risk: high
+owner: qa
+
+preconditions:
+  - signed in as agent@skyline.test / skyline
+  - a flight with exactly 1 seat remaining
+
+steps:
+  given: a flight showing "1 left"
+  when: two bookings for that flight are confirmed at the same moment
+  then: one succeeds (201 with a PNR), the other is refused (409), and seats reach 0
+
+evidence:
+  - the POST /api/bookings request and response for BOTH attempts
+  - the seat count before and after (recorded data)
+  - screenshot of the 409 "just sold" message on the losing attempt
+
+data:
+  route: JFK -> LHR
+  passengers: 1
+
+must_not:
+  - the flight must never show negative seats
+  - both bookings must never both succeed