fix(carousel): remove hasSubtitle proto field + add debug logging

- Remove hasSubtitle (field 10) from Header proto definition, index.js
  and index.d.ts - this field was adding extra bytes to encoded protobuf
  that working implementations don't send, potentially causing rejection
- Remove hasSubtitle from carousel card headers and root header
- Add [CAROUSEL DEBUG] logging in relayMessage to dump:
  - Encoded message bytes as base64 (for binary comparison)
  - Message structure as JSON
  - Per-device encoded bytes with DSM flag
- This enables byte-level comparison with working implementations

https://claude.ai/code/session_01EK9NpViRCtda1WAvFd8ptR

src/Socket/messages-send.ts

@@ -572,6 +572,26 @@ export const makeMessagesSocket = (config: SocketConfig) => {
 						}
 					}
 
+						// Debug: log per-device carousel encoding
+					const carouselInMsg = msgToEncrypt?.viewOnceMessage?.message?.interactiveMessage?.carouselMessage
+						|| msgToEncrypt?.deviceSentMessage?.message?.viewOnceMessage?.message?.interactiveMessage?.carouselMessage
+					if (carouselInMsg) {
+						try {
+							const debugBytes = proto.Message.encode(proto.Message.fromObject(msgToEncrypt)).finish()
+							logger.info(
+								{
+									recipientJid: jid,
+									isDSM: !!msgToEncrypt?.deviceSentMessage,
+									encodedBase64: Buffer.from(debugBytes).toString('base64'),
+									encodedLength: debugBytes.length,
+								},
+								'[CAROUSEL DEBUG] Per-device encoded message'
+							)
+						} catch (err) {
+							logger.warn({ jid, error: (err as Error).message }, '[CAROUSEL DEBUG] Per-device encode failed')
+						}
+					}
+
 					const bytes = encodeWAMessage(msgToEncrypt)
 					const mutexKey = jid
 
@@ -899,6 +919,28 @@ export const makeMessagesSocket = (config: SocketConfig) => {
 			messageContextInfo: message.messageContextInfo
 		}
 
+		// Debug logging for carousel messages - dump encoded bytes for binary comparison
+		if (isCarouselMessage(message)) {
+			try {
+				const msgBytes = proto.Message.encode(proto.Message.fromObject(message)).finish()
+				const meMsgBytes = proto.Message.encode(proto.Message.fromObject(meMsg)).finish()
+				logger.info(
+					{
+						msgId,
+						messageBase64: Buffer.from(msgBytes).toString('base64'),
+						meMsgBase64: Buffer.from(meMsgBytes).toString('base64'),
+						messageBytesLength: msgBytes.length,
+						meMsgBytesLength: meMsgBytes.length,
+						messageStructure: JSON.stringify(proto.Message.toObject(proto.Message.fromObject(message), { defaults: false })),
+						meMsgStructure: JSON.stringify(proto.Message.toObject(proto.Message.fromObject(meMsg), { defaults: false })),
+					},
+					'[CAROUSEL DEBUG] Encoded message bytes for binary comparison'
+				)
+			} catch (err) {
+				logger.warn({ msgId, error: (err as Error).message }, '[CAROUSEL DEBUG] Failed to encode for debug')
+			}
+		}
+
 		const extraAttrs: BinaryNodeAttributes = {}
 
 		if (participant) {

src/Utils/messages.ts

@@ -616,8 +616,7 @@ export const generateCarouselMessage = async (
 
 		const header: any = {
 			title: card.title || '',
-			hasMediaAttachment: hasMedia,
-			hasSubtitle: !!card.title
+			hasMediaAttachment: hasMedia
 		}
 
 		// Process media if present
@@ -643,7 +642,7 @@ export const generateCarouselMessage = async (
 
 	// Build the interactive message with carousel
 	const interactiveMessage: proto.Message.IInteractiveMessage = {
-		header: text ? { title: text, hasSubtitle: true } : undefined,
+		header: text ? { title: text } : undefined,
 		body: { text: text || '' },
 		footer: footer ? { text: footer } : undefined,
 		carouselMessage: {