TUI: Toggle MCPs command is missing a configurable keybind #12943

Description

Toggle MCPs exists in the TUI command list, but it has no keybind entry in the TUI keybind schema/config.
That means there is no default shortcut and no first-class config key for users to override in opencode.json.

This is inconsistent with the web app, where the equivalent command (mcp.toggle) already has a default shortcut.

Plugins

No response

OpenCode version

1.1.53AQ

Steps to reproduce

1. Open the TUI.
2. Open command list and find "Toggle MCPs".
3. Observe no default keybind shown for this command.
4. Check keybind docs/schema: no dedicated key for MCP list toggle.

Screenshot and/or share link

No response

Operating System

macOS 26.2

Terminal

Ghostty