Unify cache polling on CACHE_STATUS and split API docs.

Replace separate accel/tap snapshot UART commands with one clients[] response
that omits unsubscribed fields; remove snapshot handlers and CLI commands.
Add goTool/docs for WebSocket streams and REST; tap-snapshot REST uses CACHE_STATUS.

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

main/powerpod.c

@@ -1,10 +1,8 @@
 #include "app_config.h"
 #include "cmd_handler.h"
 #include "cmd_accel_deadzone.h"
-#include "cmd_accel_snapshot.h"
 #include "cmd_accel_stream.h"
 #include "cmd_tap_notify.h"
-#include "cmd_tap_snapshot.h"
 #include "cmd_cache_status.h"
 #include "cmd_espnow_unicast_test.h"
 #include "cmd_espnow_find_me.h"
@@ -183,10 +181,8 @@ void app_main(void) {
     cmd_version_register();
     cmd_client_info_register();
     cmd_accel_deadzone_register();
-    cmd_accel_snapshot_register();
     cmd_accel_stream_register();
     cmd_tap_notify_register();
-    cmd_tap_snapshot_register();
     cmd_cache_status_register();
     cmd_espnow_unicast_test_register();
     cmd_espnow_find_me_register();