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>

goTool/dashboard.go

@@ -643,8 +643,8 @@ func runCacheStatusDashboardPoller(link *managedSerial, hub *wsHub, interval tim
 			if err != nil {
 				continue
 			}
-			hub.mergeAccel(cache.GetAccel())
-			hub.mergeTap(cache.GetTaps())
+			hub.mergeAccel(accelSamplesFromCacheStatus(cache))
+			hub.mergeTap(tapEventsFromCacheStatus(cache))
 		}
 	}
 }