Add selectable ESP-NOW send path for accel/tap input.

Expose best_effort/fast/wait/reliable via UART, dashboard, and CLI so
loss vs latency can be compared under real multi-pod load.

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

main/powerpod.c

@@ -2,6 +2,7 @@
 #include "cmd_handler.h"
 #include "cmd_accel_deadzone.h"
 #include "cmd_accel_stream.h"
+#include "cmd_input_send_mode.h"
 #include "cmd_tap_notify.h"
 #include "cmd_tap_config.h"
 #include "cmd_cache_status.h"
@@ -221,6 +222,7 @@ void app_main(void) {
     cmd_client_info_register();
     cmd_accel_deadzone_register();
     cmd_accel_stream_register();
+    cmd_input_send_mode_register();
     cmd_tap_notify_register();
     cmd_tap_config_register();
     cmd_cache_status_register();