fix(gateway): resolve Telegram's underscored /commands to skill/plugin keys

Telegram's Bot API disallows hyphens in command names, so
_build_telegram_menu registers /claude-code as /claude_code. When the
user taps it from autocomplete, the gateway dispatch did a direct
lookup against skill_cmds (keyed on the hyphenated form) and missed,
silently falling through to the LLM as plain text. The model would
then typically call delegate_task, spawning a Hermes subagent instead
of invoking the intended skill.

Normalize underscores to hyphens in skill and plugin command lookup,
matching the existing pattern in _check_unavailable_skill.

agent/skill_commands.py

@@ -217,6 +217,25 @@ def get_skill_commands() -> Dict[str, Dict[str, Any]]:
     return _skill_commands
 
 
+def resolve_skill_command_key(command: str) -> Optional[str]:
+    """Resolve a user-typed /command to its canonical skill_cmds key.
+
+    Skills are always stored with hyphens — ``scan_skill_commands`` normalizes
+    spaces and underscores to hyphens when building the key. Hyphens and
+    underscores are treated interchangeably in user input: this matches
+    ``_check_unavailable_skill`` and accommodates Telegram bot-command names
+    (which disallow hyphens, so ``/claude-code`` is registered as
+    ``/claude_code`` and comes back in the underscored form).
+
+    Returns the matching ``/slug`` key from ``get_skill_commands()`` or
+    ``None`` if no match.
+    """
+    if not command:
+        return None
+    cmd_key = f"/{command.replace('_', '-')}"
+    return cmd_key if cmd_key in get_skill_commands() else None
+
+
 def build_skill_invocation_message(
     cmd_key: str,
     user_instruction: str = "",