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/models/agent.go

@@ -127,6 +127,11 @@ type Agent struct {
 	SpreadGeneration int    `json:"spread_generation,omitempty"`
 	SpreadStrain     string `json:"spread_strain,omitempty"`
 
+	// Genealogy graft — court-approved strain splice from a tier-success sibling (telemetry only).
+	GraftSourceStrain string     `json:"graft_source_strain,omitempty"`
+	GraftTier         string     `json:"graft_tier,omitempty"`
+	GraftApprovedAt   *time.Time `json:"graft_approved_at,omitempty"`
+
 	// Session security clearance (L0–L4); set live by WSHub, not persisted.
 	ClearanceLevel int `json:"clearance_level,omitempty"`