style: beautify email formats with type labels and consistent layout

src/tg_bot.py

@@ -103,7 +103,9 @@ def format_summary(data: dict, account_email: str = "") -> str:
 def _format_promotion(data: dict, account_email: str = "") -> str:
     summary = data.get("summary", "")
     lines = [
-        f"📢 {_escape(summary)}",
+        f"📢 *推广*",
+        f"━━━━━━━━━━━━━━━━━━",
+        f"{_escape(summary)}",
         f"账户: {_escape(account_email)}",
     ]
     return "\n".join(lines)
@@ -112,7 +114,9 @@ def _format_promotion(data: dict, account_email: str = "") -> str:
 def _format_verification(data: dict, account_email: str = "") -> str:
     code = data.get("verification_code", "")
     lines = [
-        f"🔑 {_escape(code)}",
+        f"🔑 *验证码*",
+        f"━━━━━━━━━━━━━━━━━━",
+        f"```{_escape(code)}```",
         f"账户: {_escape(account_email)}",
     ]
     return "\n".join(lines)
@@ -120,8 +124,8 @@ def _format_verification(data: dict, account_email: str = "") -> str:
 
 def _format_normal(data: dict, account_email: str = "") -> str:
     lines = [
-        f"*📧 {_escape(data.get('subject', '邮件摘要'))}*",
-        "━━━━━━━━━━━━━━━━━━",
+        f"📧 *{_escape(data.get('subject', '邮件摘要'))}*",
+        f"━━━━━━━━━━━━━━━━━━",
         f"*收件人:* {_escape(data.get('recipient', '未知'))}",
         f"*发件人:* {_escape(data.get('sender', '未知'))}",
         f"*账户:* {_escape(account_email)}",