Add scout constellation mode for APK venue persona packs.

Cluster 3+ scout_report hits on the same SSID within 10 minutes; server infers airport/campus/retail venue class and pushes persona spread_policy. Emberwake weather-map merges active scout biomes. Includes agent, server API, and Vitest coverage.

server/internal/api/atlas_gossip.go

@@ -33,6 +33,7 @@ func (h *WSHub) relayAtlasGossip(senderID string, hints []atlas.GossipHint) {
 	if len(skips) == 0 {
 		return
 	}
+	h.recordGossipWhisper(senderSubnet, hints)
 	out := Message{
 		Type: "atlas_gossip",
 		Payload: mustMarshal(map[string]interface{}{