Extract ACK codes for standalone ACKs (i.e. normal/non-flood). Might resolve #278?

app/packet_processor.py

@@ -358,6 +358,23 @@ async def process_raw_packet(
     elif payload_type == PayloadType.PATH:
         await _process_path_packet(raw_bytes, ts, packet_info)
 
+    elif payload_type == PayloadType.ACK:
+        # Standalone ACK packets carry the 4-byte ack code in cleartext (the
+        # firmware just memcpy's the uint32 into the payload). A contact answers
+        # a *direct*-routed DM with one of these, whereas a *flood*-routed DM is
+        # answered with a PATH-return that has the ACK embedded (handled above in
+        # _process_path_packet). We match directly from the raw RF packet so DM
+        # delivery confirmation does not depend on the radio also surfacing a
+        # separate EventType.ACK host control frame, which some companion
+        # firmwares (e.g. pyMC over TCP) do not reliably emit for direct ACKs.
+        if packet_info is not None and len(packet_info.payload) >= 4:
+            ack_code = packet_info.payload[:4].hex()
+            matched = await apply_dm_ack_code(ack_code, broadcast_fn=broadcast_event)
+            if matched:
+                logger.info("Applied standalone ACK %s from raw packet", ack_code)
+            else:
+                logger.debug("Buffered/ignored standalone ACK %s from raw packet", ack_code)
+
     # Always broadcast raw packet for the packet feed UI (even duplicates)
     # This enables the frontend cracker to see all incoming packets in real-time
     broadcast_payload = RawPacketBroadcast(