fix: Chat SDK bridge delivery and typing for non-Discord adapters

- Use platformId directly as thread ID in deliver() and setTyping()
  instead of calling encodeThreadId with Discord-shaped args — platformId
  is already in the adapter's encoded format (e.g. "telegram:6037840640")
- Add triggerTyping() in delivery.ts, call from router on message route
- Enable Telegram channel in barrel
- Verified E2E: Telegram message in → agent → typing indicator → response

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/delivery.ts

@@ -42,6 +42,15 @@ export function setDeliveryAdapter(adapter: ChannelDeliveryAdapter): void {
   deliveryAdapter = adapter;
 }
 
+/** Show typing indicator on a channel. Called when a message is routed to the agent. */
+export async function triggerTyping(channelType: string, platformId: string, threadId: string | null): Promise<void> {
+  try {
+    await deliveryAdapter?.setTyping?.(channelType, platformId, threadId);
+  } catch {
+    // Typing is best-effort — don't fail routing if it errors
+  }
+}
+
 /** Start the active container poll loop (~1s). */
 export function startActiveDeliveryPoll(): void {
   if (activePolling) return;