bug: slash commands not routed to GeekBot — Rocket.cat intercepts /standup

[sunba91-su]

Bug

When a user types /standup in a DM with GeekBot, the Rocket.Chat server intercepts the message (unknown slash command) and returns "Invalid command" from Rocket.cat. The message never reaches the room, so GeekBots DDP subscription never receives it.

Root Cause

Rocket.Chat processes messages starting with / server-side. If the command is not registered, the server drops the message and responds with an error — it is never delivered to the room. The DDP subscription (SubscribeToMyMessages) only receives messages that actually reach the room.

Fix

1. Register /standup as a clientOnly slash command via POST /api/v1/commands.register at startup. This tells the server the command is valid and should be passed through to the room.
2. Add !standup prefix support as a fallback — works immediately without any server permissions.

Acceptance Criteria

• /standup help in a DM with GeekBot responds from GeekBot, not Rocket.cat
• !standup help also works (fallback if registration unavailable)
• Registration failure is non-fatal (log warning, bot continues)
• All existing commands work with both / and ! prefixes