feat: drill-down filters on overview and outdated agent version highlight

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

backend/tests/test_hosts.py

@@ -1,11 +1,86 @@
 """Hosts list API."""
 
 import uuid
-from datetime import datetime, timezone
+from datetime import datetime, timedelta, timezone
 
+import pytest
+
+from app.config import get_settings
 from app.models import Event, Host, Problem
 
 
+@pytest.fixture
+def host_stale_settings(monkeypatch):
+    monkeypatch.setenv("SAC_HEARTBEAT_STALE_MINUTES", "60")
+    get_settings.cache_clear()
+    yield
+    get_settings.cache_clear()
+
+
+def test_hosts_filter_agent_status_stale(client, db_session, jwt_headers, host_stale_settings):
+    now = datetime.now(timezone.utc)
+    stale_host = Host(
+        hostname="stale-pc",
+        os_family="windows",
+        product="rdp-login-monitor",
+        last_seen_at=now,
+    )
+    fresh_host = Host(
+        hostname="fresh-pc",
+        os_family="windows",
+        product="rdp-login-monitor",
+        last_seen_at=now,
+    )
+    unknown_host = Host(
+        hostname="unknown-pc",
+        os_family="linux",
+        product="ssh-monitor",
+        last_seen_at=now,
+    )
+    db_session.add_all([stale_host, fresh_host, unknown_host])
+    db_session.flush()
+
+    db_session.add(
+        Event(
+            event_id=str(uuid.uuid4()),
+            host_id=stale_host.id,
+            occurred_at=now - timedelta(hours=2),
+            received_at=now - timedelta(hours=2),
+            category="agent",
+            type="agent.heartbeat",
+            severity="info",
+            title="hb",
+            summary="s",
+            payload={},
+        )
+    )
+    db_session.add(
+        Event(
+            event_id=str(uuid.uuid4()),
+            host_id=fresh_host.id,
+            occurred_at=now - timedelta(minutes=5),
+            received_at=now - timedelta(minutes=5),
+            category="agent",
+            type="agent.heartbeat",
+            severity="info",
+            title="hb",
+            summary="s",
+            payload={},
+        )
+    )
+    db_session.commit()
+
+    r = client.get("/api/v1/hosts?agent_status=stale", headers=jwt_headers)
+    assert r.status_code == 200
+    body = r.json()
+    assert body["total"] == 1
+    assert body["items"][0]["hostname"] == "stale-pc"
+    assert body["items"][0]["agent_status"] == "stale"
+
+    r_all = client.get("/api/v1/hosts", headers=jwt_headers)
+    assert r_all.json()["total"] == 3
+
+
 def test_hosts_search_by_display_name(client, db_session, jwt_headers):
     h = Host(
         hostname="pc-01",