Re-enable wantresponse and other fields in simradio when on the decoded path (#10934)

* Re-enable wantresponse and other fields in simradio when on the decoded path

* Make the comments less verbose

src/platform/portduino/SimRadio.cpp

@@ -252,7 +252,14 @@ void SimRadio::startSend(meshtastic_MeshPacket *txp)
 
     // pb_encode_to_bytes writes into decoded.payload, which aliases `encrypted` in the union, so all
     // reads of p->encrypted above must be complete before this point.
-    p->decoded = meshtastic_Data_init_zero;
+    if (carryEncrypted) {
+        // On the encrypted path, `decoded` aliases the ciphertext we just copied into c.data;
+        // the remaining `Data` fields hold ciphertext bytes that would serialize as spurious
+        // wire fields, so clear the struct.
+        p->decoded = meshtastic_Data_init_zero;
+    }
+    // On the decoded path, `p->decoded` is already a valid Data from perhapsDecode(),
+    // so retain the existing fields (want_response, request_id, bitfield, etc.)
     p->which_payload_variant = meshtastic_MeshPacket_decoded_tag;
     p->decoded.payload.size =
         pb_encode_to_bytes(p->decoded.payload.bytes, sizeof(p->decoded.payload.bytes), &meshtastic_Compressed_msg, &c);