fix(tctoken): add carousel exception to AB prop 10518 gate

Defensive: if WhatsApp ever flips AB prop 10518
(privacy_token_sending_on_all_1_on_1_messages) to false, the gate added
in 225b692b7c would drop the tctoken from ALL 1:1 sends — including
carousel, which Pastorini CDP capture confirms requires tctoken to
render correctly on Android.

Match the fork's pre-PR #2339 behaviour for carousel only: always
attach when a tcTokenBuffer is available. Regular 1:1 sends still
honour the AB prop.

src/Socket/messages-send.ts

@@ -1731,7 +1731,13 @@ export const makeMessagesSocket = (config: SocketConfig) => {
 			// Gate inclusion on AB prop 10518 (privacy_token_sending_on_all_1_on_1_messages).
 			// WA Web defaults to true; if the server flips it off we mirror that to avoid
 			// divergence with the spec-compliant client.
-			if (tcTokenBuffer?.length && sock.serverProps.privacyTokenOn1to1) {
+			//
+			// CARROUSEL EXCEPTION: Pastorini-validated carousel stanzas REQUIRE tctoken
+			// (CDP capture confirms it). If the AB prop ever flips off, dropping the
+			// tctoken from carousel would break rendering on Android. Carousel always
+			// includes the tctoken when one is available, regardless of the prop —
+			// matching the fork's existing behaviour pre-PR #2339.
+			if (tcTokenBuffer?.length && (sock.serverProps.privacyTokenOn1to1 || isCarousel)) {
 				;(stanza.content as BinaryNode[]).push({
 					tag: 'tctoken',
 					attrs: {},