Dissolve System Settings into individual settings pages

The monolithic tab page competed with the settings rail as a second
navigation system, and its Integrations tab was a dumping ground. Each
section is now its own routed rail page (ServiceNow, Zabbix Supplies,
Dell Warranty, Collector PC Types, Branding, Floor Map, Printing and
Labels, Email/SMTP, Audit, Authentication, Asset Identifiers, Global
Search), thin over a shared useSystemSettings composable, grouped
logically in the rail with system groups clustered last. Old
/settings/system?tab= URLs redirect to the right page.

Also fixes the post-login redirect: the auth guard now remembers the
intended destination and Login returns there (same-site paths only).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

frontend/src/router/index.js

@@ -105,7 +105,8 @@ router.beforeEach(async (to, from, next) => {
   const authStore = useAuthStore()
 
   if (to.meta.requiresAuth && !authStore.isAuthenticated) {
-    return next('/login')
+    // Remember where they were headed so login can send them back there.
+    return next({ path: '/login', query: { redirect: to.fullPath } })
   }
   if (to.meta.requiresAdmin && !authStore.isAdmin) {
     return next('/')

frontend/src/router/routes/core.js

@@ -161,10 +161,101 @@ export default [
     component: () => import('../../views/settings/EmployeeDirectory.vue'),
     meta: { requiresAuth: true, requiresAdmin: true }
   },
+  // The old monolithic System Settings tab page is split into one routed page
+  // per section (below). This redirect keeps old bookmarks working: bare
+  // /settings/system and every /settings/system?tab=<key> land on the right page.
   {
     path: 'settings/system',
     name: 'system-settings',
-    component: () => import('../../views/settings/SystemSettings.vue'),
+    redirect: to => {
+      const tabRedirects = {
+        integrations: '/settings/servicenow',
+        branding: '/settings/branding',
+        printing: '/settings/printing',
+        email: '/settings/email',
+        audit: '/settings/audit',
+        auth: '/settings/authentication',
+        identifiers: '/settings/assetidentifiers',
+        search: '/settings/globalsearch',
+        map: '/settings/floormap',
+        pctype: '/settings/pctypemapping'
+      }
+      // vue-router carries the original ?tab= query onto the target; harmless
+      // since the new pages ignore it, and the path is what routes the view.
+      return tabRedirects[to.query.tab] || '/settings/servicenow'
+    },
+    meta: { requiresAuth: true, requiresAdmin: true }
+  },
+  {
+    path: 'settings/servicenow',
+    name: 'servicenow-settings',
+    component: () => import('../../views/settings/ServiceNowSettings.vue'),
+    meta: { requiresAuth: true, requiresAdmin: true }
+  },
+  {
+    path: 'settings/zabbix',
+    name: 'zabbix-settings',
+    component: () => import('../../views/settings/ZabbixSettings.vue'),
+    meta: { requiresAuth: true, requiresAdmin: true }
+  },
+  {
+    path: 'settings/dellwarranty',
+    name: 'dell-warranty-settings',
+    component: () => import('../../views/settings/DellWarrantySettings.vue'),
+    meta: { requiresAuth: true, requiresAdmin: true }
+  },
+  {
+    path: 'settings/pctypemapping',
+    name: 'pctype-mapping-settings',
+    component: () => import('../../views/settings/PCTypeMappingSettings.vue'),
+    meta: { requiresAuth: true, requiresAdmin: true }
+  },
+  {
+    path: 'settings/branding',
+    name: 'branding-settings',
+    component: () => import('../../views/settings/BrandingSettings.vue'),
+    meta: { requiresAuth: true, requiresAdmin: true }
+  },
+  {
+    path: 'settings/printing',
+    name: 'printing-settings',
+    component: () => import('../../views/settings/PrintingSettings.vue'),
+    meta: { requiresAuth: true, requiresAdmin: true }
+  },
+  {
+    path: 'settings/email',
+    name: 'email-settings',
+    component: () => import('../../views/settings/EmailSettings.vue'),
+    meta: { requiresAuth: true, requiresAdmin: true }
+  },
+  {
+    path: 'settings/audit',
+    name: 'audit-settings',
+    component: () => import('../../views/settings/AuditSettings.vue'),
+    meta: { requiresAuth: true, requiresAdmin: true }
+  },
+  {
+    path: 'settings/authentication',
+    name: 'authentication-settings',
+    component: () => import('../../views/settings/AuthenticationSettings.vue'),
+    meta: { requiresAuth: true, requiresAdmin: true }
+  },
+  {
+    path: 'settings/assetidentifiers',
+    name: 'asset-identifiers-settings',
+    component: () => import('../../views/settings/AssetIdentifiersSettings.vue'),
+    meta: { requiresAuth: true, requiresAdmin: true }
+  },
+  {
+    path: 'settings/globalsearch',
+    name: 'global-search-settings',
+    component: () => import('../../views/settings/GlobalSearchSettings.vue'),
+    meta: { requiresAuth: true, requiresAdmin: true }
+  },
+  {
+    path: 'settings/floormap',
+    name: 'floor-map-settings',
+    component: () => import('../../views/settings/FloorMapSettings.vue'),
     meta: { requiresAuth: true, requiresAdmin: true }
   },
   {