Use `React.cache()` to deduplicate `getPage` between Page and `generateMetadata` in docs

[MODSetter]

Description

In app/docs/[[...slug]]/page.tsx, both the Page component and generateMetadata independently call source.getPage(params.slug) for the same request, duplicating CPU work.

Vercel React Best Practices Rule: server-cache-react (3.7)

File to change

• surfsense_web/app/docs/[[...slug]]/page.tsx

What to do

1. Import cache from React and create a shared cached function:

import { cache } from "react";

const getDocPage = cache((slug?: string[]) => {
  return source.getPage(slug);
});

2. Use it in both Page and generateMetadata:

export default async function Page(props: { params: Promise<{ slug?: string[] }> }) {
  const params = await props.params;
  const page = getDocPage(params.slug);
  if (!page) notFound();
  // ...
}

export async function generateMetadata(props: { params: Promise<{ slug?: string[] }> }) {
  const params = await props.params;
  const page = getDocPage(params.slug);
  if (!page) notFound();
  return { title: page.data.title, description: page.data.description };
}

React.cache() deduplicates within a single request, so the second call is a cache hit.

Acceptance criteria

• Only one getPage call executes per request (both Page and generateMetadata share the result)
• Docs pages still render with correct content and metadata
• No regressions in docs navigation

[SohamBhattacharjee2003]

Is the issue is open I would like to solve it