feat(telegram): use grammyjs/runner for concurrent update processing

Previously, grammY's default bot.start() processed updates sequentially,
blocking all Telegram messages while one was being handled. This made
maxConcurrent settings ineffective for Telegram.

Now uses @grammyjs/runner which processes updates concurrently, matching
the behavior of Discord (Promise.all) and WhatsApp (fire-and-forget).

Benefits:
- Ack reactions (👀) appear immediately, not after queue clears
- Multiple chats can be processed in parallel
- maxConcurrent setting now works correctly for Telegram
- Long-running tool calls no longer block other conversations

package.json

@@ -85,6 +85,7 @@
   "dependencies": {
     "@buape/carbon": "0.0.0-beta-20260107085330",
     "@clack/prompts": "^0.11.0",
+    "@grammyjs/runner": "^2.0.3",
     "@grammyjs/transformer-throttler": "^1.2.1",
     "@homebridge/ciao": "^1.3.4",
     "@mariozechner/pi-agent-core": "^0.37.2",