fix: OUT messages no longer create unread status + handle Telegram read receipts

Only inbound (IN) messages determine hasUnread in getContacts(). Telegram
read_business_message events are now parsed and processed to auto-mark
contacts as read for the entire team.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

omni_inbound/src/telegram.ts

@@ -30,6 +30,7 @@ function pickEventType(update: JsonObject): string {
   if (update.edited_business_message) return "edited_business_message";
   if (update.business_connection) return "business_connection";
   if (update.deleted_business_messages) return "deleted_business_messages";
+  if (update.read_business_message) return "read_business_message";
   if (update.message) return "message";
   if (update.edited_message) return "edited_message";
   return "unknown";
@@ -148,9 +149,42 @@ function makeFallbackEventId(raw: unknown) {
 
 export function parseTelegramBusinessUpdate(raw: unknown): OmniInboundEnvelopeV1 {
   const update = asObject(raw);
-  const message = pickMessage(update);
   const receivedAt = new Date().toISOString();
 
+  // Handle read_business_message separately — different payload structure
+  const readEvent = asObject(update.read_business_message);
+  if (Object.keys(readEvent).length > 0) {
+    const readChat = asObject(readEvent.chat);
+    const threadExternalId = normalizeId(readChat.id);
+    const businessConnectionId = normalizeString(readEvent.business_connection_id);
+    const updateId = update.update_id;
+    const providerEventId =
+      (updateId != null && requireString(updateId, "")) || makeFallbackEventId(raw);
+    const occurredAt = isoFromUnix(readEvent.date) ?? receivedAt;
+
+    return {
+      version: 1,
+      idempotencyKey: ["telegram_business", providerEventId, "read"].join(":"),
+      provider: "telegram_business",
+      channel: "TELEGRAM",
+      direction: "IN",
+      providerEventId,
+      providerMessageId: null,
+      eventType: "read_business_message",
+      occurredAt,
+      receivedAt,
+      payloadRaw: raw,
+      payloadNormalized: {
+        threadExternalId,
+        contactExternalId: threadExternalId,
+        text: null,
+        businessConnectionId,
+      },
+    };
+  }
+
+  const message = pickMessage(update);
+
   const updateId = update.update_id;
   const messageId = message.message_id;
   const businessConnection = asObject(update.business_connection);