docs(site): add remote-access (Tailscale/Cloudflare/ngrok) and honest iOS pages

New high-intent SEO pages:
- /remote-access/ — step-by-step Tailscale, Cloudflare Tunnel, ngrok setups
  for reaching a self-hosted opencode server from Android anywhere. HowTo +
  FAQ + BreadcrumbList structured data.
- /ios/ — honest 'no iOS app yet' page: current Android app, why, options,
  roadmap, how to follow. FAQ + BreadcrumbList structured data.

Added to sitemap.xml; internal links from index, guide, opencode-on-phone,
and troubleshooting.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs-site/troubleshooting/index.html

@@ -191,6 +191,7 @@ footer a{margin:0 8px}
       <a href="../download/">Download</a>
       <a href="../features/">Features</a>
       <a href="../guide/">Setup guide</a>
+      <a href="../remote-access/">Remote access</a>
       <a href="https://github.com/dzianisv/opencode-mobile">GitHub</a>
       <a href="../privacy/">Privacy policy</a>
     </p>