Add fleet topology epidemiology: strain plague map and mining interrupt fixes.

Strain nodes replace host nodes in FleetTopologyMap; server queues epidemiology_fix on auth and reports interrupts to AI and Seer.

server/internal/strategy/graft.go

@@ -0,0 +1,101 @@
+package strategy
+
+import (
+	"crypto/sha256"
+	"fmt"
+	"strings"
+	"time"
+)
+
+// GraftSource is the winning spread strain from agent A (tier success).
+type GraftSource struct {
+	SourceAgentID     string
+	SourceAgentName   string
+	GraftSourceStrain string
+	GraftTier         string
+	TierOrder         []string
+	PeakHashrate      float64
+}
+
+// GraftPolicy is pushed to agent B on auth; auth is never gated by genealogy.
+type GraftPolicy struct {
+	GraftSourceStrain string   `json:"graft_source_strain"`
+	GraftTier         string   `json:"graft_tier"`
+	GraftApprovedAt   string   `json:"graft_approved_at"`
+	TierOrder         []string `json:"tier_order,omitempty"`
+	SourceAgentName   string   `json:"source_agent_name,omitempty"`
+}
+
+// GraftEnabled is true when Fleet AI Control + fleet roles are on (zero extra Calibrate toggles).
+func GraftEnabled(aiControl, fleetRoles bool) bool {
+	return aiControl && fleetRoles
+}
+
+// BuildGraftSourceFromAgent extracts graft inputs from a tier-successful source agent.
+func BuildGraftSourceFromAgent(sourceID, sourceName, joinLane, spreadStrain string, tierOrder []string, peakHashrate float64) GraftSource {
+	tier := strings.TrimSpace(joinLane)
+	strain := strings.TrimSpace(spreadStrain)
+	if strain == "" && tier != "" {
+		strain = spreadStrainFromLane(tier)
+	}
+	order := normalizeTierList(tierOrder)
+	if len(order) == 0 && tier != "" {
+		order = []string{tier}
+	}
+	return GraftSource{
+		SourceAgentID:     strings.TrimSpace(sourceID),
+		SourceAgentName:   strings.TrimSpace(sourceName),
+		GraftSourceStrain: strain,
+		GraftTier:         tier,
+		TierOrder:         order,
+		PeakHashrate:      peakHashrate,
+	}
+}
+
+// SpliceGraftGenome splices source winning tier order onto target genome without re-spreading B.
+func SpliceGraftGenome(targetOrder []string, graft GraftSource) []string {
+	sourceOrder := append([]string(nil), graft.TierOrder...)
+	if len(sourceOrder) == 0 && graft.GraftTier != "" {
+		sourceOrder = []string{graft.GraftTier}
+	}
+	target := normalizeTierList(targetOrder)
+	if len(sourceOrder) == 0 {
+		return target
+	}
+	if len(target) == 0 {
+		return sourceOrder
+	}
+	return CrossbreedTierOrders(sourceOrder, target, nil, nil)
+}
+
+// GraftMetabolismGatePassed reports whether target hashrate satisfies the earn-before-graft gate.
+func GraftMetabolismGatePassed(miningHashrate, gateHPS float64) bool {
+	if gateHPS <= 0 {
+		return true
+	}
+	return miningHashrate >= gateHPS
+}
+
+// BuildGraftPolicy builds the auth/policy payload for a pending graft on agent B.
+func BuildGraftPolicy(graft GraftSource, targetOrder []string, approvedAt time.Time) GraftPolicy {
+	order := SpliceGraftGenome(targetOrder, graft)
+	if approvedAt.IsZero() {
+		approvedAt = time.Now().UTC()
+	}
+	return GraftPolicy{
+		GraftSourceStrain: graft.GraftSourceStrain,
+		GraftTier:         graft.GraftTier,
+		GraftApprovedAt:   approvedAt.UTC().Format(time.RFC3339),
+		TierOrder:         order,
+		SourceAgentName:   graft.SourceAgentName,
+	}
+}
+
+func spreadStrainFromLane(lane string) string {
+	lane = strings.TrimSpace(strings.ToLower(lane))
+	if lane == "" {
+		return ""
+	}
+	sum := sha256.Sum256([]byte("aetherforge-strain:" + lane))
+	return fmt.Sprintf("#%02x%02x%02x", sum[0], sum[1], sum[2])
+}