Docs: dashboard-tour page is linked sitewide but never routed (404) #8

Problem

src/content/docs/dashboard-tour.mdx exists. Since #4, however, src/pages/docs/[slug].astro leaves it out of the generated routes:

return docs
  .filter((doc) => doc.id !== "dashboard-tour")

/docs/dashboard-tour/ therefore returns a 404, but other parts of the site still link to it.

• Sidebar. DocsSidebar.astro builds its list from getOrderedDocs(), which still includes dashboard-tour. A local build (npm run build) shows the broken link on all 87 generated docs pages.
• Prev/Next cards. [slug].astro works out prev/next from the full ordered list, dashboard-tour included. Both neighbours of dashboard-tour in START HERE point at it. One of them is the "Next" card on Install with Helm.
• Docs index. In src/pages/docs/index.astro, the "Dashboard & create" category lists the group start-here:dashboard-tour.
• Frontmatter. dashboard-tour.mdx sets next: create-a-server. This has no effect, because [slug].astro never reads the next frontmatter override.

#7 removes only the in-body link and the next: "dashboard-tour" frontmatter from installation.mdx, which was the finding on ValgulNecron/Gameplane#520. Everything listed above is still broken.

Options

1. Publish the page. Remove the filter in [slug].astro so the page is routed, then check that dashboard-tour.mdx content and the screenshots match the current dashboard design.
2. Hide it everywhere. Filter dashboard-tour once, inside getOrderedDocs() in src/lib/docs-nav.ts. That removes it from the sidebar, the index and prev/next in one place; then delete the separate filter in [slug].astro and the start-here:dashboard-tour group entry.

Done when

• A npm run build produces no link to /docs/dashboard-tour/ unless that page is also generated. Check with grep -rl dashboard-tour dist/docs.
• If option 1 is chosen: the page matches website.pen, following the design-first rule.