1.0.1

1. • Fixed PHP 8.1+ deprecation notice — explicit string casts where null was being passed to string-typed function arguments.
   • Fixed Cannot use bool as array fatal on PHP 8.x when the slack_members cache entry hadn't been seeded yet. Cache::fetch() returns false on a miss, but the plugin was destructuring the return value directly. Now guards on is_array() before unpacking.
   • Skip all Slack API work when slack_token is empty. Previously the plugin would still hit Slack on every frontend request even without a token, paying ~200ms of network round-trip just to receive a 401 — slowing down every page on a freshly-installed-but-unconfigured site.