feat: host heartbeat status and dashboard metrics (2.2)

Track agent.heartbeat and report.daily.ssh per host; show online/stale
on Hosts UI; dashboard counters and SAC_HEARTBEAT_STALE_MINUTES config.

frontend/src/api.ts

@@ -76,6 +76,9 @@ export interface HostSummary {
   ipv4: string | null;
   last_seen_at: string;
   event_count: number | null;
+  last_heartbeat_at: string | null;
+  last_daily_report_at: string | null;
+  agent_status: "online" | "stale" | "unknown";
 }
 
 export interface HostListResponse {
@@ -116,6 +119,9 @@ export async function resolveProblem(problemId: number): Promise<{ id: number; s
 export interface DashboardSummary {
   events_last_24h: number;
   hosts_total: number;
+  hosts_stale: number;
+  heartbeats_24h: number;
+  daily_reports_24h: number;
   problems_open: number;
   severity_24h: Record<string, number>;
   recent_events: EventSummary[];

frontend/src/style.css

@@ -160,6 +160,10 @@ pre {
   margin: 0.25rem 0 0.5rem;
 }
 
+.dash-card.dash-warn {
+  border-color: #ff6b6b;
+}
+
 .severity-list {
   list-style: none;
   padding: 0;
@@ -168,6 +172,16 @@ pre {
   gap: 1rem;
 }
 
+.agent-online {
+  color: #6bcb77;
+}
+.agent-stale {
+  color: #ff6b6b;
+}
+.agent-unknown {
+  color: #9aa4b2;
+}
+
 .live-badge {
   color: #6bcb77;
   font-size: 0.85rem;

frontend/src/views/DashboardView.vue

@@ -19,6 +19,21 @@
         <div class="dash-label">Хостов</div>
         <RouterLink to="/hosts">Хосты →</RouterLink>
       </div>
+      <div class="dash-card" :class="{ 'dash-warn': data.hosts_stale > 0 }">
+        <div class="dash-value">{{ data.hosts_stale }}</div>
+        <div class="dash-label">Устаревший heartbeat</div>
+        <RouterLink to="/hosts">Хосты →</RouterLink>
+      </div>
+      <div class="dash-card">
+        <div class="dash-value">{{ data.heartbeats_24h }}</div>
+        <div class="dash-label">Heartbeat за 24 ч</div>
+        <RouterLink to="/events?type=agent.heartbeat">События →</RouterLink>
+      </div>
+      <div class="dash-card">
+        <div class="dash-value">{{ data.daily_reports_24h }}</div>
+        <div class="dash-label">Отчёты за 24 ч</div>
+        <RouterLink to="/events?type=report.daily.ssh">События →</RouterLink>
+      </div>
     </div>
 
     <h2>Severity за 24 ч</h2>
@@ -100,6 +115,9 @@ function connectLive() {
         type?: string;
         events_last_24h?: number;
         problems_open?: number;
+        hosts_stale?: number;
+        heartbeats_24h?: number;
+        daily_reports_24h?: number;
       };
       if (msg.type !== "dashboard" || !data.value) return;
       if (typeof msg.events_last_24h === "number") {
@@ -108,6 +126,15 @@ function connectLive() {
       if (typeof msg.problems_open === "number") {
         data.value.problems_open = msg.problems_open;
       }
+      if (typeof msg.hosts_stale === "number") {
+        data.value.hosts_stale = msg.hosts_stale;
+      }
+      if (typeof msg.heartbeats_24h === "number") {
+        data.value.heartbeats_24h = msg.heartbeats_24h;
+      }
+      if (typeof msg.daily_reports_24h === "number") {
+        data.value.daily_reports_24h = msg.daily_reports_24h;
+      }
     } catch {
       /* ignore malformed SSE */
     }

frontend/src/views/EventsView.vue

@@ -57,8 +57,11 @@
 
 <script setup lang="ts">
 import { onMounted, ref } from "vue";
+import { useRoute } from "vue-router";
 import { apiFetch, type EventListResponse } from "../api";
 
+const route = useRoute();
+
 const data = ref<EventListResponse | null>(null);
 const loading = ref(false);
 const error = ref("");
@@ -92,5 +95,9 @@ async function load(p: number) {
   }
 }
 
-onMounted(() => load(1));
+onMounted(() => {
+  const t = route.query.type;
+  if (typeof t === "string" && t) typeFilter.value = t;
+  load(1);
+});
 </script>

frontend/src/views/HostsView.vue

@@ -12,6 +12,9 @@
           <th>Product</th>
           <th>OS</th>
           <th>IPv4</th>
+          <th>Агент</th>
+          <th>Heartbeat</th>
+          <th>Отчёт</th>
           <th>Last seen</th>
           <th>Events</th>
         </tr>
@@ -23,6 +26,9 @@
           <td>{{ h.product }} {{ h.product_version || "" }}</td>
           <td>{{ h.os_family }}</td>
           <td>{{ h.ipv4 || "—" }}</td>
+          <td :class="'agent-' + h.agent_status">{{ agentLabel(h.agent_status) }}</td>
+          <td>{{ h.last_heartbeat_at ? formatDt(h.last_heartbeat_at) : "—" }}</td>
+          <td>{{ h.last_daily_report_at ? formatDt(h.last_daily_report_at) : "—" }}</td>
           <td>{{ formatDt(h.last_seen_at) }}</td>
           <td>{{ h.event_count ?? 0 }}</td>
         </tr>
@@ -43,6 +49,12 @@ function formatDt(iso: string) {
   return new Date(iso).toLocaleString("ru-RU");
 }
 
+function agentLabel(status: string) {
+  if (status === "online") return "online";
+  if (status === "stale") return "stale";
+  return "unknown";
+}
+
 onMounted(async () => {
   loading.value = true;
   try {