another firebase fix?

src/shared/users/user-store.ts

@@ -238,13 +238,23 @@ export function upsertUser(user: UserUpdate) {
 
   if (updates.tokenCounts) {
     for (const family of MODEL_FAMILIES) {
-      updates.tokenCounts[family] ??= { input: 0, output: 0 };
+      // Preserve existing legacy_total when creating default token counts
+      const existingCounts = existing.tokenCounts[family];
+      const defaultCounts: { input: number; output: number; legacy_total?: number } = { input: 0, output: 0 };
+      if (existingCounts?.legacy_total !== undefined) {
+        defaultCounts.legacy_total = existingCounts.legacy_total;
+      }
+      updates.tokenCounts[family] ??= defaultCounts;
+      
       // The property is now guaranteed to be an object, so the 'number' check is removed.
       // Defaulting individual fields if they are missing.
       const counts = updates.tokenCounts[family]!; // Should not be undefined here
       counts.input ??= 0;
       counts.output ??= 0;
-      // legacy_total is optional and not defaulted here if missing
+      // Preserve legacy_total from existing data if not already set in updates
+      if (counts.legacy_total === undefined && existingCounts?.legacy_total !== undefined) {
+        counts.legacy_total = existingCounts.legacy_total;
+      }
     }
   }
   if (updates.tokenLimits) {