v1.2.8: Phase 0 review fixes — snackbar.js include + sidebar 72px + collapsed view

- index.html: add snackbar.js (was missing, showSnackbar not available)
- style.css: sidebar.collapsed 56→72px (match Nubes DS 4.5rem)
- style.css: .sidebar.collapsed ~ .view margin-left: 72px

site/static/style.css

@@ -161,7 +161,7 @@ tr:hover td {
     display: flex; flex-direction: column; z-index: 100;
     transition: width .2s;
 }
-.sidebar.collapsed { width: 56px; }
+.sidebar.collapsed { width: 72px; }
 .sidebar-top {
     height: 80px; border-top: 4px solid var(--brand-primary);
     display: flex; align-items: center; padding: 0 16px;
@@ -180,6 +180,7 @@ tr:hover td {
 
 /* ── Views ── */
 .view { margin-left: 192px; padding: 16px 20px; min-height: 100vh; }
+.sidebar.collapsed ~ .view { margin-left: 72px; }
 .view.hidden { display: none; }
 .view-header { font-size: 20px; font-weight: 700; margin-bottom: 16px; }