fix(security): harden toolsBySender sender-key matching

docs/channels/slack.md

@@ -191,6 +191,8 @@ For actions/directory reads, user token can be preferred when configured. For wr
     - `skills`
     - `systemPrompt`
     - `tools`, `toolsBySender`
+    - `toolsBySender` key format: `id:`, `e164:`, `username:`, `name:`, or `"*"` wildcard
+      (legacy unprefixed keys still map to `id:` only)
 
   </Tab>
 </Tabs>