refactor: share allowFrom formatter scaffolding

extensions/discord/src/channel.ts

@@ -1,6 +1,7 @@
 import {
   buildAccountScopedDmSecurityPolicy,
   collectOpenGroupPolicyConfiguredRouteWarnings,
+  formatAllowFromLowercase,
 } from "openclaw/plugin-sdk";
 import {
   applyAccountNameToChannelSection,
@@ -116,11 +117,7 @@ export const discordPlugin: ChannelPlugin<ResolvedDiscordAccount> = {
       (resolveDiscordAccount({ cfg, accountId }).config.dm?.allowFrom ?? []).map((entry) =>
         String(entry),
       ),
-    formatAllowFrom: ({ allowFrom }) =>
-      allowFrom
-        .map((entry) => String(entry).trim())
-        .filter(Boolean)
-        .map((entry) => entry.toLowerCase()),
+    formatAllowFrom: ({ allowFrom }) => formatAllowFromLowercase({ allowFrom }),
     resolveDefaultTo: ({ cfg, accountId }) =>
       resolveDiscordAccount({ cfg, accountId }).config.defaultTo?.trim() || undefined,
   },