Add service versions panel, version auto-tracking, Fail2Ban sidebar, streaming service switch

- .github/workflows/version-bump.yml: auto-increment patch version on push to main/beta
- admin/index.php: show version under logo from VERSION file
- system.php: service-versions endpoint (catalog of 22 services with version/description/status)
- admin.js: updates page shows Installed Services table with current/latest/status/description
- admin.js: loadServiceVersions() lazy-loaded after page render via setTimeout
- admin/index.php: separate Fail2Ban sidebar entry (was merged into Firewall label)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

panel/public/admin/index.php

@@ -21,7 +21,9 @@ require_once dirname(__DIR__) . '/_branding.php';
   <aside class="sidebar" id="sidebar">
     <div class="sidebar-brand">
       <?= novacpx_logo_html('<svg class="logo-icon" viewBox="0 0 40 40" fill="none"><circle cx="20" cy="20" r="18" stroke="url(#lg1)" stroke-width="2"/><path d="M12 28 L20 8 L28 28" stroke="url(#lg2)" stroke-width="2.5" stroke-linecap="round" stroke-linejoin="round"/><path d="M14 22 H26" stroke="url(#lg2)" stroke-width="2" stroke-linecap="round"/><defs><linearGradient id="lg1" x1="2" y1="2" x2="38" y2="38"><stop offset="0%" stop-color="#6366f1"/><stop offset="100%" stop-color="#0ea5e9"/></linearGradient><linearGradient id="lg2" x1="12" y1="8" x2="28" y2="28"><stop offset="0%" stop-color="#6366f1"/><stop offset="100%" stop-color="#0ea5e9"/></linearGradient></defs></svg>') ?>
-      <span class="logo-text">Nova<strong>CPX</strong> <small style="font-size:.65rem;color:var(--text-muted)">Admin</small></span>
+      <span class="logo-text">Nova<strong>CPX</strong> <small style="font-size:.65rem;color:var(--text-muted)">Admin</small>
+        <span id="panel-version-badge" style="display:block;font-size:.6rem;color:var(--text-muted);font-weight:400;line-height:1;margin-top:2px">v<?= trim(@file_get_contents(NOVACPX_ROOT . '/VERSION') ?: NOVACPX_VERSION) ?></span>
+      </span>
     </div>
 
     <nav>