perf: sync protocol and core hardening updates

internal/store/memory/channel_recovery_test.go

@@ -0,0 +1,22 @@
+package memory
+
+import (
+	"context"
+	"testing"
+)
+
+func TestMaxChannelPtsBatchUsesOneSnapshotAndOmitsMissing(t *testing.T) {
+	channels := NewChannelStore()
+	channels.mu.Lock()
+	channels.ptsSeq[10] = 7
+	channels.ptsSeq[20] = 11
+	channels.mu.Unlock()
+
+	got, err := channels.MaxChannelPtsBatch(context.Background(), []int64{20, 999, 10, 20})
+	if err != nil {
+		t.Fatalf("MaxChannelPtsBatch: %v", err)
+	}
+	if len(got) != 2 || got[10] != 7 || got[20] != 11 {
+		t.Fatalf("batch pts = %v, want map[10:7 20:11] with missing id omitted", got)
+	}
+}