ADR-013 Phase 4: extract the 11 plugin routes embedded in core.js

core.js still routed plugin-owned pages directly. Extracted all 11 into the
owning plugin's route file + moved their views into plugins/<name>/frontend/:
- computers: reports/pc-relationships, settings/pctypemapping
- printers: reports/toner, settings/printertypes, settings/zabbix (toner/supply
  monitoring)
- machines: settings/machinetypes
- network: settings/networktypes
- warranty: settings/dellwarranty
- slides: settings/slides (its route file gains a default export; it was
  toplevel-only)
- employees: NEW plugin frontend (employees/:sso + settings/employeedirectory) -
  employees had no route file before; its pages lived only in core.js.

core.js now holds only core routes; all 14 bundled plugins are self-contained
under plugins/<name>/frontend/. Verified live: the extracted Machine Types
settings page renders in the settings rail from the machines plugin frontend.
Build + 58 vitest + naming green.

plugins/printers/frontend/views/ZabbixSettings.vue

@@ -0,0 +1,90 @@
+<template>
+  <div>
+    <div class="page-header">
+      <h2>Zabbix Supplies</h2>
+    </div>
+
+    <div class="section-card">
+      <div class="setting-group">
+        <p class="setting-description">
+          Connect to Zabbix for real-time printer supply monitoring. When enabled, supply levels
+          are fetched from Zabbix API and displayed on printer detail pages.
+        </p>
+
+        <div class="setting-row">
+          <label class="toggle-label">
+            <span>Enable Zabbix Integration</span>
+            <button
+              class="toggle-btn"
+              :class="{ active: settings.zabbix_enabled }"
+              @click="toggleSetting('zabbix_enabled')"
+              :disabled="saving"
+            >
+              <span class="toggle-slider"></span>
+            </button>
+          </label>
+        </div>
+
+        <div class="setting-row" v-if="settings.zabbix_enabled">
+          <label>
+            <span>Zabbix API URL</span>
+            <input
+              type="url"
+              v-model="settings.zabbix_url"
+              placeholder="http://zabbix.example.com:8080"
+              @blur="saveSetting('zabbix_url', settings.zabbix_url)"
+              :disabled="saving"
+            >
+          </label>
+        </div>
+
+        <div class="setting-row" v-if="settings.zabbix_enabled">
+          <label>
+            <span>Zabbix API Token</span>
+            <input
+              type="password"
+              v-model="settings.zabbix_token"
+              placeholder="Enter API token"
+              @blur="saveSetting('zabbix_token', settings.zabbix_token)"
+              :disabled="saving"
+            >
+          </label>
+        </div>
+
+        <div class="status-indicator" v-if="settings.zabbix_enabled">
+          <span class="status-dot" :class="zabbixStatus"></span>
+          <span>{{ zabbixMessage }}</span>
+        </div>
+      </div>
+    </div>
+
+    <div v-if="error" class="error-message">{{ error }}</div>
+    <div v-if="success" class="settings-success">{{ success }}</div>
+  </div>
+</template>
+
+<script setup>
+import { onMounted, computed } from 'vue'
+import { useSystemSettings } from '@/composables/systemSettings'
+
+const {
+  settings, saving, error, success,
+  loadSettings, saveSetting, toggleSetting,
+} = useSystemSettings()
+
+// Per-page connection status (stays with the page, not the composable).
+const zabbixStatus = computed(() => {
+  if (!settings.zabbix_enabled) return 'inactive'
+  if (!settings.zabbix_url || !settings.zabbix_token) return 'warning'
+  return 'pending'
+})
+
+const zabbixMessage = computed(() => {
+  if (!settings.zabbix_enabled) return 'Disabled'
+  if (!settings.zabbix_url) return 'URL not configured'
+  if (!settings.zabbix_token) return 'Token not configured'
+  return 'Configured (connectivity checked on first use)'
+})
+
+onMounted(loadSettings)
+</script>