fix(slack): add mention stripPatterns for /new and /reset commands (#9971)

* fix(slack): add mention stripPatterns for /new and /reset commands

Fixes #9937

The Slack dock was missing mentions.stripPatterns that Discord has.
This caused /new and /reset to fail when sent with a mention
(e.g. @bot /reset) because <@USERID> wasn't stripped before matching.

* fix(slack): strip mentions for /new and /reset (#9971) (thanks @ironbyte-rgb)

---------

Co-authored-by: ironbyte-rgb <amontaboi76@gmail.com>
Co-authored-by: George Pickett <gpickett00@gmail.com>

src/channels/dock.ts

@@ -295,6 +295,9 @@ const DOCKS: Record<ChatChannelId, ChannelDock> = {
       resolveRequireMention: resolveSlackGroupRequireMention,
       resolveToolPolicy: resolveSlackGroupToolPolicy,
     },
+    mentions: {
+      stripPatterns: () => ["<@[^>]+>"],
+    },
     threading: {
       resolveReplyToMode: ({ cfg, accountId, chatType }) =>
         resolveSlackReplyToMode(resolveSlackAccount({ cfg, accountId }), chatType),