docs: expand and correct website guide

[whitelonng]

What changed

• rewrote the English and Chinese documentation around the real mancode workflow contract
• added complete CLI options, file/privacy guidance, valid requirements and verification examples, and adapter capability details
• fixed code-copy behavior, localized search feedback, mobile navigation cues, and long-form readability
• synchronized the Chinese landing page and marked ZCode as a preview adapter
• added website regression tests for anchors, command order, copied examples, versions, and platform claims

Why

The previous website was a useful overview, but it was not detailed enough to study the full process and one workflow example used an invalid command order. Some CLI options and adapter capabilities were also missing or ambiguous.

Validation

• npm run lint
• npm run typecheck
• npm run build
• npx vitest run --silent — 31 files, 450 tests passed
• Playwright desktop/mobile checks for both languages, including search, clipboard output, console errors, and horizontal overflow
• Lighthouse: accessibility 100, best practices 100, SEO 100