Polish secondary Pages role copy

[YSCJRH]

Summary

• Reframe Docs, Fixes, and Starter Pages around the visitor's current task instead of generic reference labels.
• Keep the adoption order intact: demo, fixture/local run, real-site quickstart, then GitHub Action.
• Update generated-site tests so the new wording and Chinese localized paths stay locked.

Verification

• corepack pnpm build:site
• corepack pnpm seo:check
• node --experimental-strip-types --experimental-test-isolation=none --test scripts/distribution/build-site.test.ts
• corepack pnpm test
• corepack pnpm typecheck
• corepack pnpm demo:fixture
• corepack pnpm pack:cli:dry-run
• Browser review on local /zh/docs/, /zh/playbooks/, /zh/starter/, /en/docs/, /en/playbooks/, /en/starter/; console had no errors or warnings

Notes

• No new product claims, ratings, reviews, download counts, or AI answer ranking promises.
• Browser screenshot capture timed out in the in-app browser, so review used title/H1/hero text checks and DOM snapshot verification.