feat: init AI email summarization bot

- Multi-account IMAP email polling with UID tracking
- DeepSeek API integration with JSON Mode structured output
- Telegram notification with formatted MarkdownV2 message
- YAML config with dataclass-based type validation
- Graceful shutdown on SIGINT/SIGTERM
- 60s default polling interval

src/tg_bot.py

@@ -0,0 +1,56 @@
+import requests
+from src.config import TelegramConfig
+
+
+def send_message(tg_cfg: TelegramConfig, text: str):
+    url = f"https://api.telegram.org/bot{tg_cfg.bot_token}/sendMessage"
+    payload = {
+        "chat_id": tg_cfg.chat_id,
+        "text": text,
+        "parse_mode": "MarkdownV2",
+    }
+    resp = requests.post(url, json=payload, timeout=30)
+    resp.raise_for_status()
+
+
+_priority_icon = {"high": "🔴", "medium": "🟡", "low": "🟢"}
+
+
+def format_summary(data: dict) -> str:
+    priority = data.get("priority", "medium")
+    icon = _priority_icon.get(priority, "⚪")
+
+    lines = [
+        f"*📧 新邮件摘要*",
+        f"━━━━━━━━━━━━━━━━━━",
+        f"*发件人:* {_escape(data.get('sender', '未知'))}",
+        f"*主题:* {_escape(data.get('subject', '无主题'))}",
+        f"*优先级:* {icon} {priority.upper()}",
+        "",
+        _escape(data.get("summary", "")),
+        "",
+    ]
+
+    if data.get("action_required"):
+        lines.append(f"*📌 需要处理:* 是")
+        items = data.get("action_items", [])
+        if items:
+            lines.append(f"*待办事项:*")
+            for item in items:
+                lines.append(f"  • {_escape(item)}")
+        lines.append("")
+
+    points = data.get("key_points", [])
+    if points:
+        lines.append(f"*关键要点:*")
+        for p in points:
+            lines.append(f"  • {_escape(p)}")
+
+    return "\n".join(lines)
+
+
+def _escape(text: str) -> str:
+    special = "_*[]()~`>#+-=|{}.!"
+    for ch in special:
+        text = text.replace(ch, f"\\{ch}")
+    return text