fix(mattermost): keep inspector capture quiet

CHANGELOG.md

@@ -13,7 +13,7 @@ Docs: https://docs.openclaw.ai
 
 ### Fixes
 
-- Plugins/inspector: keep bundled plugin runtime capture quiet and config-tolerant for Codex, memory-lancedb, Feishu, QQBot, and Tlon so plugin-inspector JSON checks can validate the full bundled set. Thanks @vincentkoc.
+- Plugins/inspector: keep bundled plugin runtime capture quiet and config-tolerant for Codex, memory-lancedb, Feishu, Mattermost, QQBot, and Tlon so plugin-inspector JSON checks can validate the full bundled set. Thanks @vincentkoc.
 - Gateway/startup: start chat channels without waiting for primary model prewarm, keeping model warmup bounded in the background so Slack and other channels come online promptly when provider discovery is slow. Supersedes #73420. Thanks @dorukardahan.
 - Gateway/install: carry env-backed config SecretRefs such as `channels.discord.token` into generated service environments when they are present only in the installing shell, while keeping gateway auth SecretRefs non-persisted. Fixes #67817; supersedes #73426. Thanks @wdimaculangan and @ztexydt-cqh.
 - Auto-reply/commands: stop bare `/reset` and `/new` after reset hooks acknowledge the command, so non-ACP channels no longer fall through into empty provider calls while `/reset <message>` and `/new <message>` still seed the next model turn. Fixes #73367 and #73412. Thanks @hoyanhan, @wenxu007, and @amdhelper.

extensions/mattermost/src/mattermost/slash-state.ts

@@ -306,6 +306,5 @@ export function registerSlashCommandRoute(api: OpenClawPluginApi) {
       auth: "plugin",
       handler: routeHandler,
     });
-    api.logger.info?.(`mattermost: registered slash command callback at ${callbackPath}`);
   }
 }