Add compact chunked client API payload

meshtastic/mesh.options

@@ -113,8 +113,7 @@
 *MqttClientProxyMessage.data max_size:435
 *MqttClientProxyMessage.text max_size:435
 
-*ChunkedPayload.chunk_count int_size:16
-*ChunkedPayload.chunk_index int_size:16
+*ChunkedPayload.payload_size int_size:16
 *ChunkedPayload.payload_chunk max_size:228
 
 # Longest documented value is "token_wrong_size" (16 chars); 32 leaves room

meshtastic/mesh.proto

@@ -2424,6 +2424,13 @@ message FromRadio {
      * any group carries no constraint info and should not be restricted.
      */
     LoRaRegionPresetMap region_presets = 19;
+
+    /*
+     * Chunked client API payload. Only sent to clients that have opted in to
+     * chunked API transport support.
+     */
+    ChunkedPayload chunked_payload = 20;
+
   }
 }
 
@@ -2630,6 +2637,13 @@ message ToRadio {
      * Heartbeat message (used to keep the device connection awake on serial)
      */
     Heartbeat heartbeat = 7;
+
+    /*
+     * Chunked client API payload. The reassembled payload is a serialized
+     * ToRadio message and is handled through the normal PhoneAPI path.
+     */
+    ChunkedPayload chunked_payload = 8;
+
   }
 }
 
@@ -2947,24 +2961,15 @@ message NodeRemoteHardwarePin {
 
 message ChunkedPayload {
   /*
-   * The ID of the entire payload
-   */
-  uint32 payload_id = 1;
-
-  /*
-   * The total number of chunks in the payload
-   */
-  uint32 chunk_count = 2;
-
-  /*
-   * The current chunk index in the total
+   * The total size of the reassembled payload. This is sent only on the
+   * first chunk of an ordered transfer; later chunks omit it.
    */
-  uint32 chunk_index = 3;
+  uint32 payload_size = 1;
 
   /*
    * The binary data of the current chunk
    */
-  bytes payload_chunk = 4;
+  bytes payload_chunk = 2;
 }
 
 /*