fix(telegram): address review findings from PR #67816

- Update test_observed_group_context_preserves_slash_command_text_for_dispatch
  to assert user_id is preserved for COMMAND messages (new correct behavior)
- Add _coerce_allow_set helper to handle both list and comma-separated
  string allowlist inputs (prevents character-by-character iteration bug)
- Include 'channel' in chat_type checks for group-scoped authorization
- Add _telegram_extra fallback for group_allowed_chats (consistent with
  group_allow_from fallback)
- Add AUTHOR_MAP entry for nyaruko@hermes -> tsuk1nose

plugins/platforms/telegram/adapter.py

@@ -250,6 +250,7 @@ import sys
 from pathlib import Path as _Path
 sys.path.insert(0, str(_Path(__file__).resolve().parents[3]))
 
+from gateway.authz_mixin import _coerce_allow_set
 from gateway.config import Platform, PlatformConfig
 from gateway.platforms.base import (
     BasePlatformAdapter,
@@ -1016,12 +1017,12 @@ class TelegramAdapter(BasePlatformAdapter):
         # Adapter-level allow_from / group_allow_from: when set, they are the
         # sole authority.  Group chats use group_allow_from; DMs use allow_from.
         chat_type = source.chat_type or ""
-        if chat_type in ("group", "forum"):
+        if chat_type in ("group", "forum", "channel"):
             adapter_allow_from = self.config.extra.get("group_allow_from")
         else:
             adapter_allow_from = self.config.extra.get("allow_from")
         if adapter_allow_from is not None:
-            allowed = {str(u).strip() for u in adapter_allow_from if str(u).strip()}
+            allowed = _coerce_allow_set(adapter_allow_from)
             return user_id in allowed or "*" in allowed
 
         # Test/custom injection only. The class method named
@@ -9410,7 +9411,7 @@ def _apply_yaml_config(yaml_cfg: dict, telegram_cfg: dict) -> dict | None:
         if isinstance(group_allowed_users, list):
             group_allowed_users = ",".join(str(v) for v in group_allowed_users)
         os.environ["TELEGRAM_GROUP_ALLOWED_USERS"] = str(group_allowed_users)
-    group_allowed_chats = telegram_cfg.get("group_allowed_chats")
+    group_allowed_chats = telegram_cfg.get("group_allowed_chats") or _telegram_extra.get("group_allowed_chats")
     if group_allowed_chats is not None and not os.getenv("TELEGRAM_GROUP_ALLOWED_CHATS"):
         if isinstance(group_allowed_chats, list):
             group_allowed_chats = ",".join(str(v) for v in group_allowed_chats)