Stream slave accel via ESP-NOW with master snapshot cache.

Slaves push BMA456 samples at 16ms when enabled; the master caches per
client and exposes ACCEL_SNAPSHOT and ACCEL_STREAM over UART. goTool adds
dashboard stream controls, HTTP accel-stream routes, and an external
WebSocket API with per-connection receive/interval and slave stream commands.

Co-authored-by: Cursor <cursoragent@cursor.com>

main/cmd/cmd_handler.c

@@ -48,8 +48,10 @@ static const char *message_type_name(uint16_t id) {
     return "FIND_ME";
   case alox_MessageType_RESTART:
     return "RESTART";
-  case alox_MessageType_ACCEL_READ:
-    return "ACCEL_READ";
+  case alox_MessageType_ACCEL_SNAPSHOT:
+    return "ACCEL_SNAPSHOT";
+  case alox_MessageType_ACCEL_STREAM:
+    return "ACCEL_STREAM";
   default:
     return "UNKNOWN";
   }