feat(nav): finish remaining parity gaps (image_select, AJAX search, senior UI)

- Layout image_select previews (zibll PNGs under assets/images/header-layout)
- Localize aksrtAdminData.themeUri for admin SPA asset URLs
- Layout-2 inline search AJAX suggestions via aksrt_search_suggestions
- Appearance→Menus visual senior submenu editor (cards/columns)
- Acceptance checklist + automated source contract report

assets/css/frontend/nav/zib-utilities.css

@@ -130,3 +130,35 @@ body.mobile-navbar-show { overflow: hidden; }
   border-radius: 0;
   z-index: 998;
 }
+
+.navbar-inline-search-panel {
+  position: absolute;
+  left: 0;
+  top: calc(100% + 8px);
+  min-width: 280px;
+  max-width: 360px;
+  padding: 12px;
+  background: var(--main-bg-color, #fff);
+  border-radius: var(--main-radius, 8px);
+  box-shadow: 0 8px 24px rgba(0,0,0,.12);
+  z-index: 1002;
+  display: none;
+}
+.navbar-form .form-group:hover .navbar-inline-search-panel,
+.navbar-form .form-group:focus-within .navbar-inline-search-panel,
+.navbar-inline-search-panel.is-open {
+  display: block;
+  visibility: visible;
+}
+.navbar-inline-search-suggest__item {
+  display: flex;
+  flex-direction: column;
+  padding: 6px 4px;
+  color: inherit;
+  text-decoration: none;
+}
+.navbar-inline-search-suggest__item:hover { color: var(--focus-color); }
+.navbar-inline-search-hots .but { margin: 0 4px 4px 0; }
+.aksrt-sme-field { display: block; margin: 4px 0; }
+.aksrt-sme-field span { display: block; font-size: 12px; color: #646970; }
+.aksrt-sme-card, .aksrt-sme-col { border: 1px solid #dcdcde; padding: 8px; margin: 8px 0; border-radius: 4px; }