Expand P2 test coverage: mining chain, spread lanes, path forge, WS/beacon, E2E onion, file handling

server/internal/builder/genealogy.go

@@ -0,0 +1,16 @@
+package builder
+
+import (
+	"crypto/sha256"
+	"fmt"
+	"strings"
+)
+
+func spreadStrainFromJoinLane(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])
+}