fix: allow msmsg decryption and emit view-once unavailable fanout

Two issues found during view-once testing on linked devices:

1. msmsg block removal:
   The "temporary fix" that discarded all msmsg-type encrypted messages
   was also blocking legitimate view-once messages. On linked devices,
   view-once arrives as msmsg encryption type. The block was originally
   added to prevent crashes from missing messageSecret, but the existing
   try/catch in the decrypt path already handles those errors gracefully
   by marking the message as a CIPHERTEXT stub.

2. view_once_unavailable_fanout emission:
   When a linked device receives a view-once, the WA server sends only
   <unavailable type="view_once"/> (no <enc> with actual media content).
   Previously this was silently acknowledged without emitting any event,
   so consumers (zpro, astra-api, etc.) never knew a view-once arrived.
   Now it emits the message as a CIPHERTEXT stub with key.isViewOnce=true
   so consumers can display "view-once message received" in their UI.

Co-Authored-By: Renato Alcara

WAProto/WAProto.proto

@@ -1,7 +1,7 @@
 syntax = "proto3";
 package proto;
 
-/// WhatsApp Version: 2.3000.1037162330
+/// WhatsApp Version: 2.3000.1037082622
 
 message ADVDeviceIdentity {
     optional uint32 rawId = 1;

src/Defaults/baileys-version.json

@@ -1 +1 @@
-{"version":[2,3000,1037166441]}
+{"version":[2,3000,1037137890]}

src/Socket/messages-recv.ts

@@ -2377,20 +2377,12 @@ export const makeMessagesRecvSocket = (config: SocketConfig) => {
 								{ msgId: msg.key?.id, messageType },
 								'CTWA: Skipping placeholder resend for unavailable fanout type'
 							)
-							// For view-once: emit the message with a viewOnceMessage placeholder
-							// so consumers (zpro, etc.) can detect and display it.
-							// Include a message wrapper so isValidMsg accepts it.
+							// For view-once: emit the message as a stub so consumers know it arrived.
+							// Use 'notify' for live messages so realtime consumers get the event.
 							if (messageType === 'view_once_unavailable_fanout') {
 								msg.key.isViewOnce = true
-								msg.message = {
-									viewOnceMessage: {
-										message: {
-											imageMessage: {
-												viewOnce: true,
-											}
-										}
-									}
-								}
+								msg.messageStubType = proto.WebMessageInfo.StubType.CIPHERTEXT
+								msg.messageStubParameters = ['view_once_unavailable']
 								const upsertType = node.attrs.offline ? 'append' : 'notify'
 								await upsertMessage(msg, upsertType)
 							}