fix: 收敛 2925 邮箱修复范围

- 回退非必要的 2925 行为改动，仅保留已验证有效的修复
- 保留 bounce 转发地址解析、中文日期解析与邮箱页复用时的 ready 恢复
- 同步最小化测试断言，保持当前代码与测试一致

tests/background-mail2925-entry-behavior.test.js

@@ -68,7 +68,7 @@ test('ensureMail2925MailboxSession reuses current mailbox page without sending l
   });
 
   assert.equal(sendCalls, 0);
-  assert.equal(readyCalls, 0);
+  assert.equal(readyCalls, 1);
   assert.equal(result.result.usedExistingSession, true);
 });
 

tests/verification-flow-polling.test.js

@@ -43,7 +43,7 @@ test('verification flow keeps 2925 polling cadence in the default payload', () =
   assert.equal(step8Payload.intervalMs, 15000);
 });
 
-test('verification flow enables 2925 target email matching in both provide and receive modes', () => {
+test('verification flow only enables 2925 target email matching in receive mode', () => {
   const helpers = api.createVerificationFlowHelpers({
     addLog: async () => {},
     chrome: { tabs: { update: async () => {} } },
@@ -82,7 +82,7 @@ test('verification flow enables 2925 target email matching in both provide and r
     mail2925Mode: 'receive',
   });
 
-  assert.equal(providePayload.mail2925MatchTargetEmail, true);
+  assert.equal(providePayload.mail2925MatchTargetEmail, false);
   assert.equal(receivePayload.mail2925MatchTargetEmail, true);
 });