[Feature Request] Support inline model effort level specification in prompts

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Description

Users of Claude Code need to be able to specify the model effort level inline in their prompts. The inline effort level would only apply to the prompt it is embedded in. Subsequent prompts would not be affected by prior inline model effort commands and instead would get the current effort level.

Here is some proposed syntax for the inline model effort command:

• [medium] rename 'dog' to 'cat'
• [m] rename 'dog' to 'cat'
• !medium rename 'dog' to 'cat'

Inline effort specifiers are necessary because it's tedious to set the effort with /effort before the prompt and then /effort after the prompt to set it back to the original effort level.

Workaround using a local custom slash command

Note that it is possible to create local custom slash commands to do this, but slash commands are not appropriate for normal prompting since pressing the slash key causes a lot of UI drama with the completion UI popping up, the prompt input cursor moving to a different part of the screen (causing the user to lose context), and the completion functionality repainting with every keystroke. None of us wants to deal with that on every. single. prompt.

~/.claude/commands$ cat emax.md
---
effort: max
---
$ARGUMENTS