Decrease JS RPC message limit to 1MiB

src/workerd/api/worker-rpc.h

@@ -20,10 +20,9 @@
 
 namespace workerd::api {
 
-// TODO(soon): This size limit is loosely based on Cap'n Proto's 'traversalLimitInWords'.
-// JS RPC does not support streaming messages yet, and until it does we should prevent
-// large messages from being sent.
-constexpr size_t MAX_JS_RPC_MESSAGE_SIZE = 32 * 1024 * 1024;
+// TODO(soon): JS RPC does not support streaming messages yet. Until it does, we should prevent
+// large messages from being sent. This limits rpc messages to the same size as a WebSocket message.
+constexpr size_t MAX_JS_RPC_MESSAGE_SIZE = 1u << 20;
 
 // A WorkerRpc object forwards JS method calls to the remote Worker/Durable Object over RPC.
 // Since methods are not known until runtime, WorkerRpc doesn't define any JS methods.