docs: QUICK-REFERENCE "Pages 404?" snippet recommends the wrong permissions

From the v0.8.0 validation study; context QuantEcon/lectures#11.

docs/QUICK-REFERENCE.md:312-317 ("Pages 404?") recommends permissions: contents: write — wrong for native Pages deployment, and worse: a permissions: block zeroes every unlisted scope, so pasting it into a working publish workflow drops pages and id-token, breaking the configure-pages → upload-pages-artifact → deploy-pages chain at publish-gh-pages/action.yml:68-78. Same doc is right at :90-93 and :241-245.

Same pass: docs/MIGRATION-GUIDE.md:244 and docs/ARCHITECTURE.md:68 give the build-jupyter-cache key as build-{env-hash}-{run-id}, dropping the update-hash segment of build-jupyter-cache/action.yml:95; docs/QUICK-REFERENCE.md:181 is correct, and neither stale line is on another open issue. :244 sits under "Step 5: Update cache.yml" → "After (Recommended: Using build-jupyter-cache Action)", so don't "correct" it to a conda-… key. The separate setup-environment drift — docs/QUICK-REFERENCE.md:180 and setup-environment/README.md:132 give conda-{os}-{hash(env.yml)}-{version}, missing the {env-name}/py{ver} of setup-environment/action.yml:134 — is on #109, out of scope.

• docs/QUICK-REFERENCE.md:312-317 → pages: write + id-token: write
• docs/MIGRATION-GUIDE.md:244 and docs/ARCHITECTURE.md:68 → build-{env-hash}-{update-hash}-{run-id}

#109's checklist already carries "Fix #99 while in QUICK-REFERENCE.md" and #110 row 7 routes it there, so no separate PR; the cache-key lines are on no other checklist, so carry them in the same PR and close this as a duplicate of #109. Line edit only: PLAN item 10 (PLAN.md:80) proposes shrinking QUICK-REFERENCE.md to a one-screen link table, removing the troubleshooting block.

Start with the three stale references: docs/QUICK-REFERENCE.md:312-317, docs/MIGRATION-GUIDE.md:244, and docs/ARCHITECTURE.md:68. Compare them with the correct examples and the referenced action definitions at publish-gh-pages/action.yml:68-78 and build-jupyter-cache/action.yml:95. Done means the Pages permissions and cache key match the action behavior, while the setup-environment drift remains out of scope.