feat: global notification policy severity to channels (notif-22)

Singleton notification_policy table, NOTIFY_MIN_SEVERITY/CHANNELS env,
central dispatch gate, Settings policy UI, migration 007.

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/views/SettingsView.vue

@@ -11,6 +11,48 @@
     <p v-else-if="loading">Загрузка…</p>
 
     <template v-else>
+      <section class="card settings-card settings-policy">
+        <h2>Правило оповещений</h2>
+        <p class="settings-hint settings-hint-top">
+          События и problems с severity <strong>≥</strong> порога уходят в выбранные каналы (если канал включён и
+          настроен).
+        </p>
+        <form class="settings-form" @submit.prevent="savePolicy">
+          <label class="settings-field">
+            Мин. severity
+            <select v-model="policyForm.min_severity">
+              <option value="info">info</option>
+              <option value="warning">warning</option>
+              <option value="high">high</option>
+              <option value="critical">critical</option>
+            </select>
+          </label>
+          <fieldset class="settings-channels">
+            <legend>Каналы</legend>
+            <label class="settings-inline">
+              <input v-model="policyForm.use_telegram" type="checkbox" />
+              Telegram
+            </label>
+            <label class="settings-inline">
+              <input v-model="policyForm.use_webhook" type="checkbox" />
+              Webhook
+            </label>
+            <label class="settings-inline">
+              <input v-model="policyForm.use_email" type="checkbox" />
+              Email
+            </label>
+          </fieldset>
+          <p v-if="policyLoaded" class="settings-meta">
+            Источник: <code>{{ policyLoaded.source }}</code>
+          </p>
+          <div class="settings-actions">
+            <button type="submit" :disabled="savingPolicy">
+              {{ savingPolicy ? "Сохранение…" : "Сохранить правило" }}
+            </button>
+          </div>
+        </form>
+      </section>
+
       <section class="card settings-card">
         <h2>Telegram</h2>
         <form class="settings-form" @submit.prevent="saveTelegram">
@@ -18,15 +60,6 @@
             <input v-model="telegramForm.enabled" type="checkbox" />
             Включить Telegram
           </label>
-          <label class="settings-field">
-            Мин. severity
-            <select v-model="telegramForm.min_severity">
-              <option value="info">info</option>
-              <option value="warning">warning</option>
-              <option value="high">high</option>
-              <option value="critical">critical</option>
-            </select>
-          </label>
           <label class="settings-field">
             Bot token
             <input
@@ -71,15 +104,6 @@
             <input v-model="webhookForm.enabled" type="checkbox" />
             Включить webhook
           </label>
-          <label class="settings-field">
-            Мин. severity
-            <select v-model="webhookForm.min_severity">
-              <option value="info">info</option>
-              <option value="warning">warning</option>
-              <option value="high">high</option>
-              <option value="critical">critical</option>
-            </select>
-          </label>
           <label class="settings-field">
             URL
             <input
@@ -125,15 +149,6 @@
             <input v-model="emailForm.enabled" type="checkbox" />
             Включить email
           </label>
-          <label class="settings-field">
-            Мин. severity
-            <select v-model="emailForm.min_severity">
-              <option value="info">info</option>
-              <option value="warning">warning</option>
-              <option value="high">high</option>
-              <option value="critical">critical</option>
-            </select>
-          </label>
           <label class="settings-field">
             SMTP host
             <input v-model="emailForm.smtp_host" type="text" autocomplete="off" :placeholder="smtpHostPlaceholder" />
@@ -227,7 +242,16 @@ interface EmailSettings {
   source: string;
 }
 
+interface NotificationPolicy {
+  min_severity: string;
+  use_telegram: boolean;
+  use_webhook: boolean;
+  use_email: boolean;
+  source: string;
+}
+
 const loading = ref(true);
+const savingPolicy = ref(false);
 const savingTelegram = ref(false);
 const savingWebhook = ref(false);
 const savingEmail = ref(false);
@@ -239,17 +263,23 @@ const success = ref("");
 const telegramLoaded = ref<TelegramSettings | null>(null);
 const webhookLoaded = ref<WebhookSettings | null>(null);
 const emailLoaded = ref<EmailSettings | null>(null);
+const policyLoaded = ref<NotificationPolicy | null>(null);
+
+const policyForm = reactive({
+  min_severity: "warning",
+  use_telegram: true,
+  use_webhook: false,
+  use_email: false,
+});
 
 const telegramForm = reactive({
   enabled: false,
-  min_severity: "warning",
   bot_token: "",
   chat_id: "",
 });
 
 const webhookForm = reactive({
   enabled: false,
-  min_severity: "warning",
   url: "",
   secret_header: "",
   secret: "",
@@ -257,7 +287,6 @@ const webhookForm = reactive({
 
 const emailForm = reactive({
   enabled: false,
-  min_severity: "warning",
   smtp_host: "",
   smtp_port: 587,
   smtp_user: "",
@@ -298,23 +327,28 @@ async function load() {
   loading.value = true;
   error.value = "";
   try {
-    const data = await apiFetch<{ telegram: TelegramSettings; webhook: WebhookSettings; email: EmailSettings }>(
-      "/api/v1/settings/notifications",
-    );
+    const data = await apiFetch<{
+      policy: NotificationPolicy;
+      telegram: TelegramSettings;
+      webhook: WebhookSettings;
+      email: EmailSettings;
+    }>("/api/v1/settings/notifications");
+    policyLoaded.value = data.policy;
+    policyForm.min_severity = data.policy.min_severity;
+    policyForm.use_telegram = data.policy.use_telegram;
+    policyForm.use_webhook = data.policy.use_webhook;
+    policyForm.use_email = data.policy.use_email;
     telegramLoaded.value = data.telegram;
     webhookLoaded.value = data.webhook;
     emailLoaded.value = data.email;
     telegramForm.enabled = data.telegram.enabled;
-    telegramForm.min_severity = data.telegram.min_severity;
     telegramForm.bot_token = "";
     telegramForm.chat_id = "";
     webhookForm.enabled = data.webhook.enabled;
-    webhookForm.min_severity = data.webhook.min_severity;
     webhookForm.url = "";
     webhookForm.secret_header = data.webhook.secret_header ?? "";
     webhookForm.secret = "";
     emailForm.enabled = data.email.enabled;
-    emailForm.min_severity = data.email.min_severity;
     emailForm.smtp_host = "";
     emailForm.smtp_port = data.email.smtp_port || 587;
     emailForm.smtp_user = data.email.smtp_user ?? "";
@@ -330,6 +364,28 @@ async function load() {
   }
 }
 
+async function savePolicy() {
+  savingPolicy.value = true;
+  error.value = "";
+  success.value = "";
+  try {
+    policyLoaded.value = await apiFetch<NotificationPolicy>("/api/v1/settings/notifications/policy", {
+      method: "PUT",
+      body: JSON.stringify({
+        min_severity: policyForm.min_severity,
+        use_telegram: policyForm.use_telegram,
+        use_webhook: policyForm.use_webhook,
+        use_email: policyForm.use_email,
+      }),
+    });
+    success.value = "Правило оповещений сохранено.";
+  } catch (e) {
+    error.value = e instanceof Error ? e.message : "Ошибка сохранения";
+  } finally {
+    savingPolicy.value = false;
+  }
+}
+
 async function saveTelegram() {
   savingTelegram.value = true;
   error.value = "";
@@ -337,7 +393,6 @@ async function saveTelegram() {
   try {
     const body: Record<string, unknown> = {
       enabled: telegramForm.enabled,
-      min_severity: telegramForm.min_severity,
     };
     if (telegramForm.bot_token.trim()) body.bot_token = telegramForm.bot_token.trim();
     if (telegramForm.chat_id.trim()) body.chat_id = telegramForm.chat_id.trim();
@@ -363,7 +418,6 @@ async function saveWebhook() {
   try {
     const body: Record<string, unknown> = {
       enabled: webhookForm.enabled,
-      min_severity: webhookForm.min_severity,
       secret_header: webhookForm.secret_header.trim() || null,
     };
     if (webhookForm.url.trim()) body.url = webhookForm.url.trim();
@@ -422,7 +476,6 @@ async function saveEmail() {
   try {
     const body: Record<string, unknown> = {
       enabled: emailForm.enabled,
-      min_severity: emailForm.min_severity,
       smtp_port: emailForm.smtp_port,
       smtp_starttls: emailForm.smtp_starttls,
       smtp_ssl: emailForm.smtp_ssl,
@@ -505,6 +558,30 @@ onMounted(load);
   max-width: 28rem;
 }
 
+.settings-policy {
+  border-color: #3d4f66;
+}
+
+.settings-hint-top {
+  margin-top: 0;
+  margin-bottom: 1rem;
+}
+
+.settings-channels {
+  border: none;
+  padding: 0;
+  margin: 0;
+  display: flex;
+  flex-wrap: wrap;
+  gap: 1rem;
+}
+
+.settings-channels legend {
+  font-size: 0.9rem;
+  color: #9aa4b2;
+  margin-bottom: 0.35rem;
+}
+
 .settings-inline {
   flex-direction: row;
   align-items: center;