[FEATURE] Enable model switching before plan acceptance

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)

Problem Statement

When planning, I usually use Opus 4.5 and then switch to Sonnet or Haiku for implementation. However, as of now, there is no way to switch model before kicking of plan acceptance and implementation. Therefore, I have to interrupt Claude using ctrl+c, manually switch model and then ask it to continue.

1. No way to switch model before accepting plan

<img width="1062" height="286" alt="Image" src="https://github.com/user-attachments/assets/7a4de53a-fd30-4abb-bb73-539c6a5c1ba2" />

1. Have to manually interrupt execution and switch model, then ask it to continue

<img width="1456" height="372" alt="Image" src="https://github.com/user-attachments/assets/c7ac1ee1-4cba-40fb-82bd-5e8e2a903751" />

Proposed Solution

There should be an additional option, or multiple ones, something along the lines of:

Yes, auto-accept edits and change model Yes, manually approve edits and change model Yes, clear context, auto-accept edits and change model

Choosing these options should give the model switching CLI option and once the model is chosen, the plan implementation should kick off.

Alternative Solutions

I work around this currently by either:

a) choosing one of the accept plan options, interrupting Claude using ctrl+c, manually switching model and then asking it to continue

<img width="1456" height="372" alt="Image" src="https://github.com/user-attachments/assets/f9cdac66-9d24-465f-a36d-43737d5654c0" />

b) choosing the Type here to tell Claude what to change option, switching model, switching to non-plan mode and then asking Claude to implement the plan

Priority

Medium - Would be very helpful

Feature Category

CLI commands and flags

Use Case Example

1. Creating a plan using plan-mode for a new feature in my app, with Opus 4.5 as the model of choice
2. The plan has been finalised by Claude
3. I now want Claude to implement the plan but with model Sonnet 4.5 (to reduce usage)
4. I would choose a switch model and accept plan option variant
5. Switch model to Sonnet 4.5
6. Claude (with model as Sonnet 4.5) would begin plan implementation

Additional Context

There are similar issues suggesting automatic model routing for plan vs. execution modes whereas I want it to be manual after plan creation (at acceptance time).