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/views/settings/EmailSettings.vue

@@ -0,0 +1,208 @@
+<template>
+  <div>
+    <div class="page-header">
+      <h2>Email / SMTP</h2>
+    </div>
+
+    <div class="section-card">
+      <div class="setting-group">
+        <h3>Email Notifications</h3>
+        <p class="setting-description">
+          Configure SMTP settings to enable email notifications for alerts, toner reports,
+          and other system notifications.
+        </p>
+
+        <div class="setting-row">
+          <label class="toggle-label">
+            <span>Enable Email Notifications</span>
+            <button
+              class="toggle-btn"
+              :class="{ active: settings.smtp_enabled }"
+              @click="toggleSetting('smtp_enabled')"
+              :disabled="saving"
+            >
+              <span class="toggle-slider"></span>
+            </button>
+          </label>
+        </div>
+
+        <template v-if="settings.smtp_enabled">
+          <div class="settings-grid">
+            <div class="setting-row">
+              <label>
+                <span>SMTP Host</span>
+                <input
+                  type="text"
+                  v-model="settings.smtp_host"
+                  placeholder="smtp.example.com"
+                  @blur="saveSetting('smtp_host', settings.smtp_host)"
+                  :disabled="saving"
+                >
+              </label>
+            </div>
+
+            <div class="setting-row">
+              <label>
+                <span>SMTP Port</span>
+                <input
+                  type="number"
+                  v-model="settings.smtp_port"
+                  placeholder="587"
+                  @blur="saveSetting('smtp_port', settings.smtp_port)"
+                  :disabled="saving"
+                >
+              </label>
+            </div>
+
+            <div class="setting-row">
+              <label>
+                <span>Username</span>
+                <input
+                  type="text"
+                  v-model="settings.smtp_username"
+                  placeholder="username"
+                  @blur="saveSetting('smtp_username', settings.smtp_username)"
+                  :disabled="saving"
+                >
+              </label>
+            </div>
+
+            <div class="setting-row">
+              <label>
+                <span>Password</span>
+                <input
+                  type="password"
+                  v-model="settings.smtp_password"
+                  placeholder="password"
+                  @blur="saveSetting('smtp_password', settings.smtp_password)"
+                  :disabled="saving"
+                >
+              </label>
+            </div>
+          </div>
+
+          <div class="setting-row">
+            <label class="toggle-label">
+              <span>Use TLS Encryption</span>
+              <button
+                class="toggle-btn"
+                :class="{ active: settings.smtp_use_tls }"
+                @click="toggleSetting('smtp_use_tls')"
+                :disabled="saving"
+              >
+                <span class="toggle-slider"></span>
+              </button>
+            </label>
+          </div>
+
+          <div class="settings-grid">
+            <div class="setting-row">
+              <label>
+                <span>From Address</span>
+                <input
+                  type="email"
+                  v-model="settings.smtp_from_address"
+                  placeholder="noreply@example.com"
+                  @blur="saveSetting('smtp_from_address', settings.smtp_from_address)"
+                  :disabled="saving"
+                >
+              </label>
+            </div>
+
+            <div class="setting-row">
+              <label>
+                <span>From Name</span>
+                <input
+                  type="text"
+                  v-model="settings.smtp_from_name"
+                  placeholder="ShopDB"
+                  @blur="saveSetting('smtp_from_name', settings.smtp_from_name)"
+                  :disabled="saving"
+                >
+              </label>
+            </div>
+          </div>
+
+          <div class="setting-row full-width">
+            <label>
+              <span>Default Alert Recipients</span>
+              <input
+                type="text"
+                v-model="settings.alert_recipients"
+                placeholder="user1@example.com, user2@example.com"
+                @blur="saveSetting('alert_recipients', settings.alert_recipients)"
+                :disabled="saving"
+              >
+              <small class="input-hint">Comma-separated list of email addresses</small>
+            </label>
+          </div>
+
+          <div class="status-indicator">
+            <span class="status-dot" :class="smtpStatus"></span>
+            <span>{{ smtpMessage }}</span>
+          </div>
+
+          <button
+            class="test-btn"
+            @click="testEmail"
+            :disabled="saving || testingEmail || !canTestEmail"
+          >
+            {{ testingEmail ? 'Sending...' : 'Send Test Email' }}
+          </button>
+        </template>
+      </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, ref, computed } from 'vue'
+import { useSystemSettings } from '../../composables/systemSettings'
+import { apiError } from '../../utils/apiError'
+
+const {
+  settings, saving, error, success,
+  loadSettings, saveSetting, toggleSetting,
+} = useSystemSettings()
+
+const testingEmail = ref(false)
+
+// Per-page connection status (stays with the page, not the composable).
+const smtpStatus = computed(() => {
+  if (!settings.smtp_enabled) return 'inactive'
+  if (!settings.smtp_host || !settings.smtp_from_address) return 'warning'
+  return 'pending'
+})
+
+const smtpMessage = computed(() => {
+  if (!settings.smtp_enabled) return 'Disabled'
+  if (!settings.smtp_host) return 'SMTP host not configured'
+  if (!settings.smtp_from_address) return 'From address not configured'
+  return 'Configured - use test button to verify'
+})
+
+const canTestEmail = computed(() => {
+  return settings.smtp_host && settings.smtp_from_address && settings.alert_recipients
+})
+
+async function testEmail() {
+  // TODO: Implement test email endpoint
+  testingEmail.value = true
+  error.value = ''
+  success.value = ''
+  try {
+    // await settingsApi.testEmail()
+    success.value = 'Test email feature coming soon'
+  } catch (e) {
+    error.value = apiError(e, 'Failed to send test email')
+  } finally {
+    testingEmail.value = false
+    setTimeout(() => { success.value = '' }, 3000)
+  }
+}
+
+onMounted(loadSettings)
+</script>