fixed stale state after logout and replayed or lost share intents

lib/api/request_cache.dart

@@ -3,8 +3,10 @@ import 'dart:convert';
 
 import 'package:localstore/localstore.dart';
 
+import '../model/account_data.dart';
 import 'api_response.dart';
 import 'errors/parse_exception.dart';
+import 'errors/stale_session_exception.dart';
 
 abstract class RequestCache<T extends ApiResponse?> {
   static const int cacheNothing = 0;
@@ -48,6 +50,7 @@ abstract class RequestCache<T extends ApiResponse?> {
   static void ignore(Exception e) {}
 
   Future<void> start(String document) async {
+    final epoch = AccountData().sessionEpoch;
     try {
       final tableData = await Localstore.instance
           .collection(collection)
@@ -67,6 +70,12 @@ abstract class RequestCache<T extends ApiResponse?> {
 
       try {
         final newValue = await onLoad();
+        // The collection is shared, so a late response of a signed-out
+        // account would otherwise be cached for the next one.
+        if (!AccountData().isCurrentSession(epoch)) {
+          onError(const StaleSessionException());
+          return;
+        }
         onUpdate?.call(newValue);
         onNetworkData?.call(newValue);
         unawaited(
@@ -141,8 +150,10 @@ Future<T> resolveFromCache<T extends ApiResponse?>(
     onError?.call(e);
   });
   await cache.ready;
-  if (latest != null) return latest as T;
   final err = capturedError;
+  // `latest` may still hold the cache hit read before the sign-out.
+  if (err is StaleSessionException) throw err;
+  if (latest != null) return latest as T;
   if (err != null) throw err;
   throw ParseException(
     technicalDetails: operationName != null