[FEATURE] Frequent context information in claude -p stream-json

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 want to know what's current context size while updates are coming through

Proposed Solution

please add a flag or something and send a json line with this information after every update

Alternative Solutions

just have manually stop and check in interactive mode

Priority

High - Significant impact on productivity

Feature Category

CLI commands and flags

Use Case Example

I am working on a simple agent that helps with my stuff, while i'd like avoid long context

Additional Context

_No response_