WP-02: encrypted settings, SMTP mail, job runner and cron scheduler

AES-256-GCM secret storage keyed by MASTER_KEY, SMTP settings with test mail
(lettre), persisted job runs with log and status, JobRunner with per-kind
concurrency guard, 6-field cron schedules with defaults, scheduler loop.
Settings and Jobs pages in the UI. FAKE_HOST mode for dev machines.

Tests: 30 application, 8 infrastructure, 23 API, 16 Vitest, 6 Playwright.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

frontend/src/components/AppShell.vue

@@ -9,6 +9,7 @@ const nav = [
   { to: '/updates', label: 'Updates' },
   { to: '/vulnerabilities', label: 'Vulnerabilities' },
   { to: '/backups', label: 'Backups' },
+  { to: '/jobs', label: 'Jobs' },
   { to: '/users', label: 'Users', admin: true },
   { to: '/settings', label: 'Settings' },
 ]

frontend/src/components/SmtpForm.vue

@@ -0,0 +1,104 @@
+<script setup lang="ts">
+import { ref } from 'vue'
+import type { SmtpPayload, SmtpSecurity, SmtpView } from '../api/types'
+
+const props = defineProps<{ current?: SmtpView | null; busy?: boolean }>()
+const emit = defineEmits<{ submit: [payload: SmtpPayload] }>()
+
+const host = ref(props.current?.host ?? '')
+const port = ref(props.current?.port ?? 587)
+const security = ref<SmtpSecurity>(props.current?.security ?? 'starttls')
+const username = ref(props.current?.username ?? '')
+const password = ref('')
+const from = ref(props.current?.from ?? '')
+const notifyTo = ref(props.current?.notify_to.join(', ') ?? '')
+
+function submit() {
+  emit('submit', {
+    host: host.value,
+    port: Number(port.value),
+    security: security.value,
+    username: username.value,
+    password: password.value,
+    from: from.value,
+    notify_to: notifyTo.value
+      .split(/[,;\s]+/)
+      .map((s) => s.trim())
+      .filter(Boolean),
+  })
+}
+const input = 'mt-1 w-full rounded-md border border-gray-300 px-3 py-2'
+</script>
+
+<template>
+  <form class="grid max-w-xl gap-4" @submit.prevent="submit">
+    <div class="grid grid-cols-3 gap-4">
+      <div class="col-span-2">
+        <label for="smtp-host" class="block text-sm font-medium">SMTP host</label>
+        <input id="smtp-host" v-model="host" name="host" required :class="input" />
+      </div>
+      <div>
+        <label for="smtp-port" class="block text-sm font-medium">Port</label>
+        <input
+          id="smtp-port"
+          v-model="port"
+          name="port"
+          type="number"
+          min="1"
+          max="65535"
+          required
+          :class="input"
+        />
+      </div>
+    </div>
+    <div>
+      <label for="smtp-security" class="block text-sm font-medium">Security</label>
+      <select id="smtp-security" v-model="security" name="security" :class="input">
+        <option value="starttls">STARTTLS</option>
+        <option value="tls">TLS</option>
+        <option value="none">None</option>
+      </select>
+    </div>
+    <div>
+      <label for="smtp-user" class="block text-sm font-medium">Username</label>
+      <input id="smtp-user" v-model="username" name="username" :class="input" />
+    </div>
+    <div>
+      <label for="smtp-pass" class="block text-sm font-medium">Password</label>
+      <input
+        id="smtp-pass"
+        v-model="password"
+        name="password"
+        type="password"
+        autocomplete="new-password"
+        :class="input"
+      />
+      <p v-if="current?.password_set" class="mt-1 text-xs text-gray-500">
+        A password is stored, leave empty to keep it.
+      </p>
+    </div>
+    <div>
+      <label for="smtp-from" class="block text-sm font-medium">From address</label>
+      <input id="smtp-from" v-model="from" name="from" type="email" required :class="input" />
+    </div>
+    <div>
+      <label for="smtp-to" class="block text-sm font-medium">Notification recipients</label>
+      <input
+        id="smtp-to"
+        v-model="notifyTo"
+        name="notify_to"
+        placeholder="ops@example.com, dev@example.com"
+        :class="input"
+      />
+    </div>
+    <div>
+      <button
+        type="submit"
+        :disabled="busy"
+        class="rounded-md bg-blue-600 px-4 py-2 text-sm text-white hover:bg-blue-700 disabled:opacity-50"
+      >
+        Save SMTP settings
+      </button>
+    </div>
+  </form>
+</template>