[FEATURE] Add "Chat about this" for proposed plan

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

On plan mode, claude suggests a comperhensive plan, but it sometimes may contradict core features / mechanics / systems. Sometimes, to pick the best design, I would like to have a complete conversation with claude, allowing to pinpoint fault area's in the plan and its core design and allowing discussion on the available options.
Claude-code only allows accepting the plan, rejecting it, or refine it.
There is no option to discuss about this plan (as new context), and have pros/cons discussion.

Proposed Solution

Have an ability to chat with claude-code about proposed plans.

When claude-code handles the initial request for a plan, it may ask back questions. when presented with options, it usually has 2 available options, with brief description per each option, and a recommended option. If none of the options suffice there is a "Chat about it", which allows having conversation with claude-code about it.

This will be great if I could use this option within plan-mode, after plan was established.

Alternative Solutions

The only alternative I currently have is creating an additional session, and paste the current plan as a reference along with the task requirement.

Priority

Medium - Would be very helpful

Feature Category

Interactive mode (TUI)

Use Case Example

Define a task - feature / refactoring / etc.
Invoke claude-code with the task of designing a plan to implement the task.
Claude-code presents the plan.
The plan does not take into consideration all integration parts.
Chat with claude why these sections were not taken into consideration in the plan. Also, I may have a deeper discussion locating more issues to applied over this plan.

Additional Context

_No response_