Consolidate settings into 8 hubs and fix security vulnerabilities

Settings Consolidation (37+ pages to 8 hubs):
- Asset Type Hub: Unified type management with plugin descriptors
- Model Catalog Hub: Vendors, types, models, operating systems
- Asset Configuration Hub: Statuses, relationships, fields, identifiers
- Security Hub: Authentication, tokens, users, audit
- Site Configuration Hub: Site settings, floor map, branding, imports
- Integrations Hub: ServiceNow, Zabbix, Dell warranty
- Locations Hub: Locations, business units, employees
- Network Infrastructure Hub: VLANs, subnets

Plugin Descriptor Pattern:
- Add get_asset_type_descriptor hook to BasePlugin
- Implement descriptors in 6 plugins (printers, computers, machines, network, measuringtools, locations)
- Add /api/pluginui/asset-type-descriptors and core-type-descriptors endpoints
- Generic SubtypesTab component renders CRUD UI from descriptor schema

Security Fixes:
- Fix stored XSS via javascript: URIs in Models and Support Teams
- Add URL scheme validation (allow only http/https) in create/update endpoints
- Fix plugin contract violations in endpoints plugin (use shopdb.api imports)
- Add missing requiresAdmin guard to printer model supplies route
- Add user-facing error messages to API token load failures

Integration Improvements:
- Add persistent tab navigation to ServiceNow, Zabbix, and Dell Warranty settings
- Standardize integration settings UI across all three pages
- Fix tab visibility when navigating between integrations

Tested with 94-agent orchestrated review for ADR compliance and security.

plugins/printers/frontend/routes.js

@@ -26,6 +26,12 @@ export default [
     component: () => import('./views/ZabbixSettings.vue'),
     meta: { requiresAuth: true, requiresAdmin: true, plugin: 'printers' }
   },
+  {
+    path: 'settings/integrations/zabbix',
+    name: 'integrations-zabbix',
+    component: () => import('./views/ZabbixSettings.vue'),
+    meta: { requiresAuth: true, requiresAdmin: true, plugin: 'printers' }
+  },
   {
     path: 'settings/printer-alerts',
     name: 'printer-alerts',
@@ -61,7 +67,7 @@ export default [
     path: 'settings/modelsupplies',
     name: 'model-supplies',
     component: () => import('./views/ModelSuppliesList.vue'),
-    meta: { requiresAuth: true, plugin: 'printers' }
+    meta: { requiresAuth: true, requiresAdmin: true, plugin: 'printers' }
   },
   {
     path: 'settings/printerdrivers',

plugins/printers/frontend/views/ZabbixSettings.vue

@@ -1,7 +1,32 @@
 <template>
   <div>
     <div class="page-header">
-      <h2>Zabbix Supplies</h2>
+      <h2>Integrations</h2>
+      <p class="header-description">Configure external service connections and APIs</p>
+    </div>
+
+    <div class="integration-tabs">
+      <router-link
+        :to="{ name: 'servicenow-settings' }"
+        class="integration-tab"
+        :class="{ active: $route.name === 'servicenow-settings' }"
+      >
+        ServiceNow
+      </router-link>
+      <router-link
+        :to="{ name: 'zabbix-settings' }"
+        class="integration-tab"
+        :class="{ active: $route.name === 'zabbix-settings' }"
+      >
+        Zabbix Supplies
+      </router-link>
+      <router-link
+        :to="{ name: 'dell-warranty-settings' }"
+        class="integration-tab"
+        :class="{ active: $route.name === 'dell-warranty-settings' }"
+      >
+        Dell Warranty
+      </router-link>
     </div>
 
     <div class="section-card">
@@ -88,3 +113,39 @@ const zabbixMessage = computed(() => {
 
 onMounted(loadSettings)
 </script>
+
+<style scoped>
+.header-description {
+  margin: 0.5rem 0 0;
+  color: var(--text-light);
+  font-size: 0.95rem;
+}
+
+.integration-tabs {
+  display: flex;
+  gap: 0.25rem;
+  border-bottom: 1px solid var(--border-color);
+  background: var(--bg-secondary);
+  margin: 2rem 0;
+}
+
+.integration-tab {
+  padding: 0.75rem 1.5rem;
+  text-decoration: none;
+  color: var(--text-light);
+  border-bottom: 2px solid transparent;
+  transition: all 0.15s;
+  font-weight: 500;
+  font-size: 0.95rem;
+}
+
+.integration-tab:hover {
+  color: var(--text);
+  background: var(--hover-bg);
+}
+
+.integration-tab.active {
+  color: var(--primary);
+  border-bottom-color: var(--primary);
+}
+</style>

plugins/printers/plugin.py

@@ -678,3 +678,16 @@ class PrintersPlugin(BasePlugin):
             return None
         # _computer_by_hostname returns the (Computer, Asset) pair.
         return row[1].assetid
+
+    def get_asset_type_descriptor(self):
+        """Return descriptor for printer types management in Asset Type Hub."""
+        return {
+            'assettype': 'printer',
+            'subtype_endpoint': '/printers/types',
+            'subtype_id_field': 'printertypeid',
+            'subtype_label_field': 'printertype',
+            'subtype_description_field': 'description',
+            'subtype_color_field': 'color',
+            'optional_tabs': [],
+            'edit_permission': 'printers.manage',
+        }