fix(kanban): cover remaining add_notify_sub call sites for chat_type (#56580)

Follow-up to the main fix in this PR. rodriguez46p-ui's review on the
equivalent #56632 (closed stale) flagged that only the auto-subscribe
path in tools/kanban_tools.py was covered; the same gap existed in two
more call sites:

- gateway/slash_commands.py: the `/kanban create` slash command auto-
  subscribes the calling session but didn't pass chat_type. Read it
  from source.chat_type (already available on SessionSource).
- hermes_cli/kanban.py: the `kanban notify-subscribe` CLI command now
  accepts --chat-type and threads it through.

The dashboard plugin API (plugins/kanban/dashboard/plugin_api.py) still
has the gap because the home_channel config schema doesn't carry
chat_type — that's a follow-up that needs a config schema change.

Verified: 258 tests pass on the kanban + session_context suites.

hermes_cli/kanban.py

@@ -771,6 +771,7 @@ def build_parser(parent_subparsers: argparse._SubParsersAction) -> argparse.Argu
     p_nsub.add_argument("task_id")
     p_nsub.add_argument("--platform", required=True)
     p_nsub.add_argument("--chat-id", required=True)
+    p_nsub.add_argument("--chat-type", default="", help="dm / group / channel (used by wake routing)")
     p_nsub.add_argument("--thread-id", default=None)
     p_nsub.add_argument("--user-id", default=None)
     p_nsub.add_argument(
@@ -2758,6 +2759,7 @@ def _cmd_notify_subscribe(args: argparse.Namespace) -> int:
         kb.add_notify_sub(
             conn, task_id=args.task_id,
             platform=args.platform, chat_id=args.chat_id,
+            chat_type=args.chat_type,
             thread_id=args.thread_id, user_id=args.user_id,
             notifier_profile=args.notifier_profile or _profile_author(),
         )