fix: address codex/copilot review on view-once send/recv

P1 (messages-recv.ts): remove early return for <unavailable type="view_once"/>.
decryptMessageNode already handles this gracefully — decode-wa-message.ts sets
fullMessage.key.isViewOnce=true and skips the CIPHERTEXT stub (line 464).
The early return was preventing upsertMessage from emitting an event to consumers,
making view-once sends from the primary phone invisible on linked devices.

P2 (messages-send.ts): restrict isViewOnceMsg detection to actual view-once media.
Previously checked only for the presence of viewOnceMessage* wrappers, which are
also used by buttons/lists/carousels (non-view-once). Now unwraps the inner message
and checks imageMessage.viewOnce / videoMessage.viewOnce / audioMessage.viewOnce,
consistent with the detection in decode-wa-message.ts. Prevents companion DSM
filtering from incorrectly applying to interactive messages.

P3 (messages-send.ts): move assertSessions to use only the recipients actually
encrypted for. For view-once, omitted companions no longer cause assertSessions
to fail or do unnecessary session validation work.

Co-Authored-By: Renato Alcara

src/Socket/messages-recv.ts

@@ -2258,17 +2258,6 @@ export const makeMessagesRecvSocket = (config: SocketConfig) => {
 			return
 		}
 
-		// Handle view-once unavailable sync from primary device.
-		// When the primary device sends a view-once, linked companions receive
-		// <unavailable type="view_once"/> — no enc content, just a sync signal.
-		// Acknowledge and skip decryption (nothing to decrypt).
-		const unavailableNode = getBinaryNodeChild(node, 'unavailable')
-		if (unavailableNode?.attrs?.type === 'view_once') {
-			logger.debug({ id: node.attrs.id, from: node.attrs.from }, 'received view_once unavailable sync from primary device')
-			await sendMessageAck(node)
-			return
-		}
-
 		const {
 			fullMessage: msg,
 			category,

src/Socket/messages-send.ts

@@ -1277,21 +1277,32 @@ export const makeMessagesSocket = (config: SocketConfig) => {
 					: otherRecipients
 				const effectiveAllRecipients = [...effectiveMeRecipients, ...effectiveOtherRecipients]
 
-				await assertSessions(effectiveAllRecipients)
+				// P2: detect actual view-once media by checking inner message's viewOnce flag.
+				// viewOnceMessage wrapper is also used for interactive messages (buttons, lists, etc)
+				// which do NOT carry viewOnce=true on the media — those must NOT be filtered.
+				const viewOnceInner =
+					message.viewOnceMessageV2?.message ||
+					message.viewOnceMessage?.message ||
+					message.viewOnceMessageV2Extension?.message
+				const isViewOnceMsg = !!(
+					viewOnceInner?.imageMessage?.viewOnce ||
+					viewOnceInner?.videoMessage?.viewOnce ||
+					viewOnceInner?.audioMessage?.viewOnce
+				)
 
 				// For view-once: only send DSM to primary phone (device=0).
 				// Companion devices (device>0) are omitted — WA server generates
 				// <unavailable type="view_once"/> for them automatically.
 				// Sending explicit <unavailable> from a companion is rejected by the server.
-				const isViewOnceMsg = !!(
-					message.viewOnceMessageV2 ||
-					message.viewOnceMessage ||
-					message.viewOnceMessageV2Extension
-				)
 				const viewOnceMeRecipients = isViewOnceMsg
 					? effectiveMeRecipients.filter(jid => !jidDecode(jid)?.device)
 					: effectiveMeRecipients
 
+				// P3: assert sessions only for recipients we actually encrypt for.
+				// For view-once, companions are omitted — asserting their sessions is wasteful
+				// and could block the send if a companion session is corrupted.
+				await assertSessions([...viewOnceMeRecipients, ...effectiveOtherRecipients])
+
 				const [
 					{ nodes: meNodes, shouldIncludeDeviceIdentity: s1 },
 					{ nodes: otherNodes, shouldIncludeDeviceIdentity: s2 }