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

.gitignore

@@ -0,0 +1,4 @@
+.venv/
+__pycache__/
+*.pyc
+config.yaml