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>

.gitignore

@@ -1,3 +1,4 @@
 node_modules/
 data/
 *.log
+qa/out/