feat(queue): add ACK handling and SMP response multiplexing for subscribed connections

- Implement queue_send_ack() with pending_msg buffer for MSG/OK disambiguation
- Add SMP response type detection on subscribed connections (OK/MSG/ERR)
- Add Reply Queue diagnostic logging for SUB, listen loop, and ratchet state
- Re-SUB before listen loop to ensure active subscription
- Identified but not yet fixed: missing ACK after ConnInfo reception on Q_B
- Add impressum.md

Aufträge: 45a, 45b, 45e | Session: 24

Author: cannatoshi

docs/legal/impressum.md

@@ -1,12 +1,12 @@
 ---
-title: "Legal Notice (Impressum)"
+title: "Legal Notice (Imprint)"
 sidebar_position: 99
 unlisted: true
 ---
 
-# Legal Notice (Impressum)
+# Legal Notice (Imprint)
 
-Required under German law (TMG, MStV).
+Required under German law (§ 5 DDG).
 
 ## Provider
 

main/include/smp_queue.h

@@ -13,7 +13,7 @@
 // Queue ID sizes
 #define QUEUE_ID_SIZE       24
 #define DH_PUBLIC_SIZE      32
-#define AUTH_KEY_SIZE       32
+#define AUTH_KEY_SIZE        32
 
 // Our created queue info
 typedef struct {
@@ -82,6 +82,17 @@ bool queue_reconnect(void);
  */
 bool queue_send_key(const uint8_t *peer_auth_key_spki, int key_len);
 
+/**
+ * Send ACK command to acknowledge a received message.
+ * Must be called after processing each MSG to unblock the queue.
+ * Auftrag 45a.
+ *
+ * @param msg_id      Message ID from MSG command (server nonce)
+ * @param msg_id_len  Length of message ID
+ * @return true if server accepted ACK
+ */
+bool queue_send_ack(const uint8_t *msg_id, int msg_id_len);
+
 /**
  * Encode our queue as SMPQueueInfo for AgentConnInfoReply
  */