Show context usage percentage in plan approval prompt

Problem

When Claude Code presents the plan approval prompt, the status line (which displays context usage %) is hidden by the prompt overlay:

Claude has written up a plan and is ready to execute. Would you like to proceed?

 ❯ 1. Yes, clear context and auto-accept edits (shift+tab)
   2. Yes, auto-accept edits

This makes it difficult to make an informed decision about whether to choose option 1 ("clear context") since you can't see how much context has been used.

Suggested Solution

Include the current context usage percentage directly in the approval prompt:

Claude has written up a plan and is ready to execute. Would you like to proceed?
Context: 45.2% used

 ❯ 1. Yes, clear context and auto-accept edits (shift+tab)
   2. Yes, auto-accept edits

Current Workaround

Press Escape to dismiss the prompt, check context usage in the status line, then re-trigger plan execution.

Why This Matters

• Option 1 clears context to save tokens, but without knowing current usage, users can't judge if this is necessary
• Users with custom status lines configured specifically to monitor context usage lose that visibility at the exact moment it's most relevant