feat: host display_name в ingest, поиск хостов, UI и docs

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

backend/app/services/ingest.py

@@ -46,7 +46,9 @@ def upsert_host(db: Session, payload: dict) -> Host:
         db.add(host)
     else:
         host.hostname = hostname
-        host.display_name = host_data.get("display_name") or host.display_name
+        dn = host_data.get("display_name")
+        if isinstance(dn, str) and dn.strip():
+            host.display_name = dn.strip()
         host.os_version = host_data.get("os_version") or host.os_version
         host.product_version = source.get("product_version") or host.product_version
         host.ipv4 = host_data.get("ipv4") or host.ipv4