refactor(src): split oversized modules

src/gateway/protocol/schema/error-codes.ts

@@ -0,0 +1,22 @@
+import type { ErrorShape } from "./types.js";
+
+export const ErrorCodes = {
+  NOT_LINKED: "NOT_LINKED",
+  AGENT_TIMEOUT: "AGENT_TIMEOUT",
+  INVALID_REQUEST: "INVALID_REQUEST",
+  UNAVAILABLE: "UNAVAILABLE",
+} as const;
+
+export type ErrorCode = (typeof ErrorCodes)[keyof typeof ErrorCodes];
+
+export function errorShape(
+  code: ErrorCode,
+  message: string,
+  opts?: { details?: unknown; retryable?: boolean; retryAfterMs?: number },
+): ErrorShape {
+  return {
+    code,
+    message,
+    ...opts,
+  };
+}