refactor: dedupe embeddings error formatter

src/gateway/embeddings-http.ts

@@ -3,6 +3,7 @@ import type { IncomingMessage, ServerResponse } from "node:http";
 import { resolveAgentDir } from "../agents/agent-scope.js";
 import { resolveMemorySearchConfig } from "../agents/memory-search.js";
 import { loadConfig } from "../config/config.js";
+import { formatErrorMessage } from "../infra/errors.js";
 import { logWarn } from "../logger.js";
 import {
   getMemoryEmbeddingProvider,
@@ -85,10 +86,6 @@ function validateInputTexts(texts: string[]): string | undefined {
   return undefined;
 }
 
-function formatErrorMessage(err: unknown): string {
-  return err instanceof Error ? err.message : String(err);
-}
-
 function resolveAutoExplicitProviders(cfg: ReturnType<typeof loadConfig>): Set<string> {
   return new Set(
     listMemoryEmbeddingProviders(cfg)