feat(commands): unify chat commands (#275)

* Chat commands: registry, access groups, Carbon

* Chat commands: clear native commands on disable

* fix(commands): align command surface typing

* docs(changelog): note commands registry (PR #275)

---------

Co-authored-by: Peter Steinberger <steipete@gmail.com>

src/auto-reply/templating.ts

@@ -28,8 +28,11 @@ export type MsgContext = {
   SenderE164?: string;
   /** Provider label (whatsapp|telegram|discord|imessage|...). */
   Provider?: string;
+  /** Provider surface label (e.g. discord, slack). Prefer this over `Provider` when available. */
+  Surface?: string;
   WasMentioned?: boolean;
   CommandAuthorized?: boolean;
+  CommandSource?: "text" | "native";
 };
 
 export type TemplateContext = MsgContext & {