docs(website): add Local AI setup guide and chat modes docs

Restructure getting started to cover Local AI and Cloud AI options
with Hybrid support. Add Chat Modes section documenting Code Mode,
Planning Mode, and Implement Action. Expand Settings with Local AI
tab, Configuration, and Experiments details. Update tools page and
add changelog entry for File Explorer drag-to-move fix.

src/pages/changelog.astro

@@ -54,6 +54,7 @@ import BaseLayout from '../layouts/BaseLayout.astro';
                 <li><strong>Zaguán Coder Daemon.</strong> Fixed a bug where it reconnected to the provider in a longer session.</li>
                 <li><strong>Zaguán Coder Daemon.</strong> Wired up <code>zlp_request</code>. It was planned, but missing.</li>
                 <li><strong>Zaguán Coder Daemon.</strong> Fixed loading the History in Zaguán Blade.</li>
+              <li><strong>File Explorer.</strong> Fixed a bug where moving files was not possible using the mouse.</li>
               </ul>
             </div>
           </div>