Initial commit: Telegram bot with Cloudflare Workers

- OpenAI GPT-4o-mini with Function Calling
- Cloudflare D1 for user profiles and message buffer
- Sliding window (3 summaries max) for infinite context
- Tools: weather, search, time, calculator
- Workers AI fallback support
- Webhook security with rate limiting

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

wrangler.toml

@@ -0,0 +1,20 @@
+name = "telegram-summary-bot"
+main = "src/index.ts"
+compatibility_date = "2024-01-01"
+
+[ai]
+binding = "AI"
+
+[vars]
+SUMMARY_THRESHOLD = "20"
+MAX_SUMMARIES_PER_USER = "3"
+N8N_WEBHOOK_URL = "https://n8n.anvil.it.com"
+
+[[d1_databases]]
+binding = "DB"
+database_name = "telegram-conversations"
+database_id = "c285bb5b-888b-405d-b36f-475ae5aed20e"
+
+# Secrets (wrangler secret put 으로 설정):
+# - BOT_TOKEN: Telegram Bot Token
+# - WEBHOOK_SECRET: Webhook 검증용 시크릿