Add server subnet discovery store, API, and agent policy push.

server/internal/api/fleet_spread_host.go

@@ -93,6 +93,17 @@ func (f *FleetHandler) PostSpreadToHost(w http.ResponseWriter, r *http.Request)
 		lane.Lane,
 	)
 
+	_ = (&OathLedgerBridge{DB: f.db, Hub: f.ws}).Record(
+		AuthUsername(r), dbpkg.OathSpreadDiscoveredHost, seedID, "", dbpkg.OathOutcomeSuccess,
+		map[string]string{"host": req.Host, "finding": req.Finding, "join_lane": lane.Lane},
+		map[string]string{"host": req.Host, "finding": req.Finding},
+	)
+	if f.db != nil {
+		if row, err := f.db.MarkSubnetDiscoverySpreadAttempted(req.Host); err == nil && row != nil && f.ws != nil {
+			f.ws.BroadcastSubnetDiscoveryUpdate(*row)
+		}
+	}
+
 	writeJSON(w, map[string]interface{}{
 		"ok":                  true,
 		"host":                req.Host,