MBTI64-PUBLIC-PROFILE-V8_5-UI-POLISH-01

[fermatmind]

What changed

• Added a sticky local section navigation on the personality detail page for V8.5/V5 long-form public profiles.
• Improved spacing, card rhythm, scanability, and responsive density for backend-supplied MBTI64 reader-experience sections.
• Added contract coverage so the sticky local nav remains part of the public personality detail surface.

Why

• V8.5/V5 personality assets are much longer and need a clearer reading path, faster section access, and better mobile scanability.
• This keeps content authority in backend CMS/API while improving the frontend rendering experience.

Validation

• pnpm exec vitest run tests/contracts/personality-sections.contract.test.tsx tests/contracts/personality-type-browse.contract.test.tsx
• pnpm test:contract
• pnpm typecheck
• pnpm lint .
• NEXT_PUBLIC_API_URL=https://api.fermatmind.com NEXT_PUBLIC_SITE_URL=https://fermatmind.com pnpm build
• git diff --check
• Playwright smoke for /zh/personality/intj-a at desktop and mobile viewports; screenshots written to /tmp/mbti64-v85-ui-polish-desktop.png and /tmp/mbti64-v85-ui-polish-mobile.png

Deferred

• No CMS writes.
• No editorial content changes.
• No approval queue, promotion, publish, index/search, sitemap, or llms changes.
• No production deploy.

Repository rule impact

• This PR keeps personality content backend-authoritative and only changes frontend rendering/layout behavior for CMS/API-provided content.