ci: establish zero-warning lint baseline

[fermatmind]

What changed

• cleared the existing ESLint warning baseline across assessment hooks, MBTI result components, CMS media renderers, scripts, and tests
• enforced pnpm lint . --max-warnings=0 in CI while retaining the changed-file warning gate
• synchronized the MBTI PDF print-asset hash after scoped MBTI result component cleanup

Why

The production guard race fix requires a reliable repository-wide zero-warning lint gate. Existing warnings prevented that gate from being enabled without masking future regressions.

Validation

• pnpm lint . --max-warnings=0
• pnpm typecheck
• focused contracts: 4 files / 51 tests
• pnpm test:contract: 4 shards / 4,127 tests passed
• NEXT_PUBLIC_SITE_URL=https://fermatmind.com NEXT_PUBLIC_API_URL=https://api.fermatmind.com pnpm build
• node scripts/ops/check-mbti-pdf-print-asset-hash.mjs --check
• git diff --check
• exact changed-file scope review

Deferred

• production required-check polling and race handling remains isolated to the next PR
• no CMS, SEO authority, sitemap/llms, deployment, or server changes are included