QA harness: qa/run.sh + walk.mjs (public + member/admin) + earn.mjs (earning flows)

Headless Playwright checks that boot a throwaway local copy for anything that
signs in or writes; npm run qa / qa:public / qa:member / qa:earn.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

package.json

@@ -4,7 +4,7 @@
   "private": true,
   "description": "InstantAdPay membership advertising site - immutable on-chain settlement, transparent ledger.",
   "main": "server.js",
-  "scripts": {"start": "node server.js", "dev": "node --watch server.js"},
+  "scripts": {"start": "node server.js", "dev": "node --watch server.js", "qa": "bash qa/run.sh all", "qa:public": "bash qa/run.sh public", "qa:member": "bash qa/run.sh member", "qa:earn": "bash qa/run.sh earn"},
   "engines": {"node": ">=20"},
   "dependencies": {"mysql2": "^3.11.0", "qrcode": "^1.5.4"}
 }