feat: add chat group daily summarizer

- Telegram collector (Telethon MTProto) with checkpoint-based message fetching
- Claude API summarization via proxy (haiku model)
- Dashboard page with date picker, markdown summary, raw message drill-down
- Separate container lifecycle from dashboard for stable Telethon sessions
- Shared SQLite DB mounted read-only into dashboard

chat-summarizer/summarizer.py

@@ -0,0 +1,77 @@
+import os
+import logging
+from datetime import datetime, timedelta, timezone
+import aiosqlite
+import httpx
+from db import DB_PATH
+
+log = logging.getLogger(__name__)
+
+API_KEY = os.environ.get("ANTHROPIC_API_KEY", "")
+BASE_URL = os.environ.get("ANTHROPIC_BASE_URL", "https://www.bytecatcode.org")
+MODEL = "claude-haiku-4-5-20251001"
+CST = timezone(timedelta(hours=8))
+
+PROMPT = """You are a chat group digest assistant. Summarize the following chat messages into a concise daily digest.
+
+Rules:
+- Group by topic/theme, not by chat group
+- Highlight key decisions, shared links, and action items
+- Skip greetings, small talk, and low-value chatter
+- Use markdown formatting
+- Write in the same language as the messages (likely Chinese)
+- Be concise
+
+Messages:
+{messages}"""
+
+async def summarize(date_str: str = None):
+    now = datetime.now(CST)
+    if not date_str:
+        date_str = now.strftime("%Y-%m-%d")
+
+    start = datetime.strptime(date_str, "%Y-%m-%d").replace(tzinfo=CST)
+    end = start + timedelta(days=1)
+
+    async with aiosqlite.connect(DB_PATH) as db:
+        cursor = await db.execute(
+            "SELECT group_name, sender_name, text, timestamp FROM messages WHERE timestamp >= ? AND timestamp < ? ORDER BY timestamp",
+            (start.isoformat(), end.isoformat())
+        )
+        rows = await cursor.fetchall()
+
+    if not rows:
+        log.info("No messages for %s, skipping summary", date_str)
+        return None
+
+    # Format messages for the prompt
+    formatted = []
+    for group_name, sender, text, ts in rows:
+        formatted.append(f"[{group_name}] {sender}: {text}")
+    messages_text = "\n".join(formatted)
+
+    # Call Claude API
+    async with httpx.AsyncClient(timeout=120) as client:
+        resp = await client.post(
+            f"{BASE_URL}/v1/messages",
+            headers={"x-api-key": API_KEY, "anthropic-version": "2023-06-01", "content-type": "application/json"},
+            json={
+                "model": MODEL,
+                "max_tokens": 4096,
+                "messages": [{"role": "user", "content": PROMPT.format(messages=messages_text)}]
+            }
+        )
+        resp.raise_for_status()
+        data = resp.json()
+        summary = data["content"][0]["text"]
+
+    # Store summary
+    async with aiosqlite.connect(DB_PATH) as db:
+        await db.execute(
+            "INSERT OR REPLACE INTO summaries (date, content, created_at) VALUES (?,?,?)",
+            (date_str, summary, now.isoformat())
+        )
+        await db.commit()
+
+    log.info("Generated summary for %s (%d messages)", date_str, len(rows))
+    return summary