[FEATURE] Allow for updated input in `PermissionRequest:ExitPlanTool:Approve` hook

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

I would like to be able to send additional feedback along with approval of a plan with PermissionRequest hook responds with behavior:allow (for tool ExitPlanMode). For instance, accepting a plan but guiding Claude with additional instructions for the plan. This is useful for users who work with spec-driven development.

See a user request here: https://github.com/backnotprop/plannotator/issues/7

Related to #15755

Proposed Solution

Within the hook tool call sequence for approving a plan, iePermissionRequest:ExitPlanTool:Approve, please add the ability to submit extra context.

"hookSpecificOutput": {
"hookEventName": "PermissionRequest",
"decision": {
"behavior": "allow",
"updatedInput": {
"plan": "{full_plan}", // or:
"appendToPlan": "{extra details}"
}
}
}
}

Alternative Solutions

_No response_

Priority

Medium - Would be very helpful

Feature Category

Other

Use Case Example

Plugin, check it out.

https://github.com/backnotprop/plannotator/issues/7

Additional Context

_No response_