Feature request: Hide individual built-in slash commands & show effort level in status line

Feature Request

1. Allow hiding individual built-in slash commands

Currently, / autocomplete shows all built-in commands. Users who don't use certain commands (e.g., /stickers, /mobile, /passes) find them cluttering the list.

Custom skills support user-invocable: false to hide from the menu, but there's no equivalent for built-in commands. --disable-slash-commands disables everything, which is too aggressive.

Proposed: A setting like "hiddenCommands": ["/stickers", "/mobile"] in settings.json to hide specific commands from the autocomplete list.

2. Show effort level in the status line

The current effort level (low/medium/high/max) is not visible in the status line. Users have to run /effort without arguments to check. It would be helpful to have an option to always display the current effort level in the status line, either as a built-in status line variable or via the custom status line configuration.