harden state durability and disable destructive snapshot sync

convex/state.ts

@@ -23,6 +23,7 @@ export const saveSnapshot = mutation({
   args: {
     snapshot: v.any(),
     updatedAt: v.string(),
+    syncToDomain: v.optional(v.boolean()),
   },
   handler: async (ctx, args) => {
     const latest = await ctx.db
@@ -30,7 +31,10 @@ export const saveSnapshot = mutation({
       .order("desc")
       .first();
 
-    const syncSummary = await syncFromEngineSnapshot(ctx, args.snapshot);
+    const shouldSync = Boolean(args.syncToDomain);
+    const syncSummary = shouldSync
+      ? await syncFromEngineSnapshot(ctx, args.snapshot)
+      : null;
 
     if (latest) {
       await ctx.db.patch(latest._id, {