fix: improve Hotmail IMAP code extraction and OpenAI mail diagnostics

- 合并 PR #177 的核心改动：补齐 Hotmail helper 在 IMAP 场景下的完整正文提码与 OpenAI 邮件日志输出
- 本地补充修复：无
- 影响范围：scripts/hotmail_helper.py、tests/hotmail_helper_logging_test.py

tests/hotmail_helper_logging_test.py

@@ -18,6 +18,107 @@ hotmail_helper = load_hotmail_helper()
 
 
 class HotmailHelperLoggingTest(unittest.TestCase):
+    def test_select_latest_code_can_use_full_body_when_preview_is_truncated(self):
+        css_prefix = (
+            'Your temporary ChatGPT verification code '
+            '@font-face { font-family: "Söhne"; src: url(https://cdn.openai.com/common/fonts/soehne/soehne-buch.woff2) format("woff2"); } '
+            '.ExternalClass { width: 100%; } '
+            '#bodyTable { width: 560px; } '
+            'body { min-width: 100% !important; } '
+        ) * 8
+        full_body = (
+            css_prefix
+            + 'Enter this temporary verification code to continue: 272964 '
+            + 'Please ignore this email if this was not you.'
+        )
+        message = {
+            "id": "imap-1",
+            "mailbox": "INBOX",
+            "subject": "Your temporary ChatGPT verification code",
+            "from": {
+                "emailAddress": {
+                    "address": "otp@tm1.openai.com",
+                    "name": "OpenAI",
+                }
+            },
+            "bodyPreview": full_body[:500],
+            "body": {
+                "content": full_body,
+            },
+            "receivedTimestamp": 200,
+        }
+
+        result = hotmail_helper.select_latest_code(
+            [message],
+            ['openai', 'noreply', 'verify', 'auth', 'chatgpt', 'duckduckgo', 'forward'],
+            ['verify', 'verification', 'code', '验证码', 'confirm', 'login'],
+            [],
+            0,
+        )
+
+        self.assertEqual(result["code"], "272964")
+        self.assertEqual(result["message"]["id"], "imap-1")
+
+    def test_log_openai_messages_logs_full_body_when_available(self):
+        messages = [{
+            "mailbox": "INBOX",
+            "subject": "Your verification code",
+            "from": {
+                "emailAddress": {
+                    "address": "account-security@openai.com",
+                    "name": "OpenAI",
+                }
+            },
+            "bodyPreview": "Use 123456 to continue.",
+            "body": {
+                "content": "Hello there\nUse 123456 to continue.",
+            },
+        }]
+
+        output = io.StringIO()
+        with redirect_stdout(output):
+            hotmail_helper.log_openai_messages(messages, transport="imap")
+
+        rendered = output.getvalue()
+        self.assertIn(
+            "[HotmailHelper] openai mail received transport=imap mailbox=INBOX sender=account-security@openai.com senderName=OpenAI subject=Your verification code",
+            rendered,
+        )
+        self.assertIn(
+            "[HotmailHelper] openai mail full body start transport=imap mailbox=INBOX sender=account-security@openai.com senderName=OpenAI subject=Your verification code",
+            rendered,
+        )
+        self.assertIn("Hello there\nUse 123456 to continue.", rendered)
+        self.assertIn("[HotmailHelper] openai mail full body end", rendered)
+
+    def test_log_openai_messages_falls_back_to_preview_without_full_body(self):
+        messages = [{
+            "mailbox": "Junk",
+            "subject": "Verify your sign in",
+            "from": {
+                "emailAddress": {
+                    "address": "noreply@tm.openai.com",
+                    "name": "ChatGPT",
+                }
+            },
+            "bodyPreview": "Use 654321 to continue.",
+        }]
+
+        output = io.StringIO()
+        with redirect_stdout(output):
+            hotmail_helper.log_openai_messages(messages, transport="graph")
+
+        rendered = output.getvalue()
+        self.assertIn(
+            "[HotmailHelper] openai mail received transport=graph mailbox=Junk sender=noreply@tm.openai.com senderName=ChatGPT subject=Verify your sign in",
+            rendered,
+        )
+        self.assertIn(
+            "[HotmailHelper] openai mail preview transport=graph mailbox=Junk sender=noreply@tm.openai.com senderName=ChatGPT subject=Verify your sign in preview=Use 654321 to continue.",
+            rendered,
+        )
+        self.assertNotIn("openai mail full body start", rendered)
+
     def test_refresh_access_token_logs_invalid_grant_and_direct_connection_refused_separately(self):
         failures = [
             {
@@ -38,7 +139,8 @@ class HotmailHelperLoggingTest(unittest.TestCase):
             },
         ]
 
-        with mock.patch.object(hotmail_helper, "try_refresh_access_token", side_effect=failures):
+        with mock.patch.object(hotmail_helper, "try_refresh_access_token", side_effect=failures), \
+             mock.patch.object(hotmail_helper, "get_proxy_debug_context", return_value="direct"):
             output = io.StringIO()
             with redirect_stdout(output):
                 with self.assertRaises(RuntimeError):