refactor: dedupe extension lowercase helpers

extensions/imessage/src/normalize.ts

@@ -47,7 +47,7 @@ export function normalizeIMessageHandle(raw: string): string {
       return "";
     }
     const value = trimmed.slice(prefix.length).trim();
-    return `${prefix.toLowerCase()}${value}`;
+    return `${normalizeLowercaseStringOrEmpty(prefix)}${value}`;
   }
   if (trimmed.includes("@")) {
     return normalizeLowercaseStringOrEmpty(trimmed);

extensions/imessage/src/probe.ts

@@ -3,6 +3,7 @@ import { loadConfig } from "openclaw/plugin-sdk/config-runtime";
 import { runCommandWithTimeout } from "openclaw/plugin-sdk/process-runtime";
 import type { RuntimeEnv } from "openclaw/plugin-sdk/runtime-env";
 import { detectBinary } from "openclaw/plugin-sdk/setup";
+import { normalizeLowercaseStringOrEmpty } from "openclaw/plugin-sdk/text-runtime";
 import { createIMessageRpcClient } from "./client.js";
 import { DEFAULT_IMESSAGE_PROBE_TIMEOUT_MS } from "./constants.js";
 
@@ -35,7 +36,7 @@ async function probeRpcSupport(cliPath: string, timeoutMs: number): Promise<RpcS
   try {
     const result = await runCommandWithTimeout([cliPath, "rpc", "--help"], { timeoutMs });
     const combined = `${result.stdout}\n${result.stderr}`.trim();
-    const normalized = combined.toLowerCase();
+    const normalized = normalizeLowercaseStringOrEmpty(combined);
     if (normalized.includes("unknown command") && normalized.includes("rpc")) {
       const fatal = {
         supported: false,

extensions/imessage/src/test-plugin.ts

@@ -21,7 +21,7 @@ function normalizeIMessageTestHandle(raw: string): string {
   }
   if (/^(chat_id:|chat_guid:|chat_identifier:)/i.test(trimmed)) {
     return trimmed.replace(/^(chat_id:|chat_guid:|chat_identifier:)/i, (match) =>
-      match.toLowerCase(),
+      normalizeLowercaseStringOrEmpty(match),
     );
   }
   if (trimmed.includes("@")) {