阶段4-tool契约: register支持CapabilityMeta(决策8 meta可选+新能力强制), 新增registerAll显式注册入口双入口过渡(决策9), RUNTIME_ERROR_CODES错误码固化+audit校验, 规范v1同步收紧

packages/rpa-core/src/index.ts

@@ -10,6 +10,11 @@ export { register, getHandler, hasCapability, capabilityIds, capabilityCount } f
 export { runFlow } from "./engine/runtime";
 export { RuntimeError, BreakSignal, ContinueSignal, StopSignal, asRuntimeError } from "./engine/types";
 export { setSubflowSource, getSubflowSource, type SubflowSource } from "./engine/host-bridge";
+// 错误契约（任务 4.3）：稳定错误码枚举 + 机器可读结构（RuntimeError.code / recommendation / detail 等）
+export { RUNTIME_ERROR_CODES, isKnownErrorCode, type ErrorCode } from "./engine/error-codes";
+// 能力元数据（任务 4.1）与显式注册入口（任务 4.2，双入口过渡）
+export { getCapabilityMeta, type CapabilityMeta, type CapabilityParamMeta } from "./engine/registry";
+export { registerAll, capabilityDomains } from "./capabilities/register-all";
 export {
   setHostBridge,
   getHostBridge,