Public web-only release: SvxPortal front-end + auth backend, install templates and INSTALL.md

Stripped from the internal repo: per-box deploy trees, Go services (nodelist/astmeta/proxy/svxdr),
deploy/sync scripts and all secrets. Config templates for nginx, PHP-FPM, Redis and tmpfiles
live in install/ with CHANGEME placeholders.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

help.js

@@ -0,0 +1,24 @@
+'use strict';
+
+// Tab switching for help.html. Deep-linkable: #build, #setup, #admin, #portal.
+(function(){
+  const tabs = document.getElementById('helpTabs');
+  if (!tabs) return;
+
+  function show(name){
+    document.querySelectorAll('.tab-section').forEach(s =>
+      s.classList.toggle('d-none', s.id !== 'tab-' + name));
+    tabs.querySelectorAll('button').forEach(b =>
+      b.classList.toggle('active', b.dataset.tab === name));
+  }
+
+  tabs.addEventListener('click', e => {
+    const b = e.target.closest('button[data-tab]');
+    if (!b) return;
+    show(b.dataset.tab);
+    history.replaceState(null, '', '#' + b.dataset.tab);
+  });
+
+  const h = location.hash.replace('#', '');
+  if (h && document.getElementById('tab-' + h)) show(h);
+})();