♻️ Refactor synchronization service

internal/syncer/merge/merger.go

@@ -0,0 +1,19 @@
+package merge
+
+import (
+	"context"
+	"voidraft/internal/syncer/snapshot"
+)
+
+// Report 描述一次合并中的统计信息。
+type Report struct {
+	Added     int
+	Updated   int
+	Deleted   int
+	Conflicts int
+}
+
+// Merger 描述快照合并策略。
+type Merger interface {
+	Merge(ctx context.Context, local *snapshot.Snapshot, remote *snapshot.Snapshot) (*snapshot.Snapshot, Report, error)
+}