feat: add group activation command

src/gateway/protocol/schema.ts

@@ -291,6 +291,9 @@ export const SessionsPatchParamsSchema = Type.Object(
     key: NonEmptyString,
     thinkingLevel: Type.Optional(Type.Union([NonEmptyString, Type.Null()])),
     verboseLevel: Type.Optional(Type.Union([NonEmptyString, Type.Null()])),
+    groupActivation: Type.Optional(
+      Type.Union([Type.Literal("mention"), Type.Literal("always"), Type.Null()]),
+    ),
     syncing: Type.Optional(
       Type.Union([Type.Boolean(), NonEmptyString, Type.Null()]),
     ),