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

dashboard/frontend/src/App.svelte

@@ -7,6 +7,7 @@
   import Terminal from "./routes/Terminal.svelte";
   import OpenClaw from "./routes/OpenClaw.svelte";
   import Settings from "./routes/Settings.svelte";
+  import ChatSummary from "./routes/ChatSummary.svelte";
   import Login from "./routes/Login.svelte";
   import { onMount } from "svelte";
   import { getToken, checkAuth, setToken, setRefreshToken } from "./lib/api.js";
@@ -92,6 +93,8 @@
           <Terminal />
         {:else if page === "openclaw"}
           <OpenClaw />
+        {:else if page === "chat-digest"}
+          <ChatSummary />
         {:else if page === "settings"}
           <Settings />
         {/if}