Replace the hand-maintained public robots.txt and sitemap.xml with

App Router metadata routes so crawl directives and sitemap output

come from code instead of drifting static files.

Centralize the current locale route list in a shared SEO route

helper and generate all existing localized URLs from that source.

The sitemap now includes localized alternates for the current

homepage, privacy, terms, and support routes while keeping the

existing trailing-slash URL shape and export-friendly behavior.

Update the visible homepage messaging across en, ja, zh-Hans, and

zh-Hant to explain BitRemote more clearly as a remote download

manager for NAS, seedbox, and home server workflows.

Keep the existing layout and components unchanged while improving

the hero, benefit frames, quickstart steps, pricing lead-in, FAQ

answers, and App Store CTA wording for clarity and stronger search

alignment.

Introduce reusable JSON-LD helpers for SoftwareApplication,

FAQPage, and BreadcrumbList schema so the current locale routes

can emit structured data from the same localized content source.

Add SoftwareApplication and FAQPage schema to the localized

homepage, and breadcrumb schema to the support, privacy, and

terms pages without changing the existing UI layout.

Introduce the reusable landing page component, typed downloader

content model, and shared metadata builder that future downloader

pages will use.

This commit does not publish any new routes yet; it only prepares

the rendering and SEO plumbing so English pages can be added in

the next task and localized later without redesigning the current

text-UI layout.

Publish the new downloader landing route for English and populate

content for aria2, qBittorrent, Transmission, Synology Download

Station, and QNAP Download Station.

Wire those pages into locale-aware metadata, breadcrumb schema, and

the generated sitemap while only advertising English alternates for

now so the new URLs do not point at untranslated pages.

Add downloader landing page content for zh-Hant, zh-Hans, and ja

using the same typed registry introduced for English.

Because the route, metadata, and sitemap are already driven from that

registry, this automatically expands static params and language

alternates for the new localized downloader pages without changing

the landing page component or route structure.

Close the remaining integration gaps from the SEO rollout by

linking the homepage downloader list to the new landing pages and

updating sitemap alternates to include every localized downloader

page for each slug.

This keeps landing pages discoverable through both internal links

and sitemap coverage, and aligns the sitemap hreflang output with

the localized downloader content now present in the registry.