fix: v0.1.11 — fix crypto_box decryption with session pubkeys

Store sender's sessionPubkey on message_queue at send time.
drainForMember returns COALESCE(sender_session_pubkey, peer_pubkey)
so the recipient gets the correct sender key for decryption.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/broker/src/index.ts

@@ -438,6 +438,7 @@ async function handleSend(
   const messageId = await queueMessage({
     meshId: conn.meshId,
     senderMemberId: conn.memberId,
+    senderSessionPubkey: conn.sessionPubkey ?? undefined,
     targetSpec: msg.targetSpec,
     priority: msg.priority,
     nonce: msg.nonce,