fix: missing <style> tag breaks zh/ page; correct canonical URLs

[Copilot]

website/zh/index.html was missing its opening <style> tag, causing the entire CSS block to render as raw text in the browser. Additionally, both index.html and zh/index.html had canonical/hreflang URLs pointing to /cast/ instead of the actual deployment path /cast-cli/.

Changes

• website/zh/index.html — Insert missing <style> tag before the CSS :root block:

  <link rel="alternate" hreflang="zh-CN" href="...">
  <style>       <!-- was absent -->
    :root {
      --bg: #0D0C0B;
      ...

• website/zh/index.html / website/index.html — Fix canonical and hreflang URLs: /cast/ → /cast-cli/

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[github-actions]

🔍 Preview ready

Page	URL
EN homepage	https://castops.github.io/cast-cli/pr-8/
ZH homepage	https://castops.github.io/cast-cli/pr-8/zh/
Docs (EN)	https://castops.github.io/cast-cli/pr-8/docs/getting-started.html
Docs (ZH)	https://castops.github.io/cast-cli/pr-8/zh/docs/getting-started.html

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