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/db.py

@@ -0,0 +1,33 @@
+import aiosqlite
+import os
+
+DB_PATH = os.environ.get("DB_PATH", "/app/data/chat_summary.db")
+
+async def init_db():
+    async with aiosqlite.connect(DB_PATH) as db:
+        await db.execute("""
+            CREATE TABLE IF NOT EXISTS messages (
+                id INTEGER PRIMARY KEY AUTOINCREMENT,
+                group_id INTEGER NOT NULL,
+                group_name TEXT,
+                sender_name TEXT,
+                text TEXT,
+                msg_id INTEGER,
+                timestamp DATETIME NOT NULL
+            )
+        """)
+        await db.execute("""
+            CREATE TABLE IF NOT EXISTS summaries (
+                id INTEGER PRIMARY KEY AUTOINCREMENT,
+                date TEXT UNIQUE NOT NULL,
+                content TEXT NOT NULL,
+                created_at DATETIME DEFAULT CURRENT_TIMESTAMP
+            )
+        """)
+        await db.execute("""
+            CREATE TABLE IF NOT EXISTS checkpoints (
+                group_id INTEGER PRIMARY KEY,
+                last_msg_id INTEGER NOT NULL
+            )
+        """)
+        await db.commit()