[FEATURE] Feature request: flag to hide chat history when using --fork-session

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

Use case
We run a nightly cron job that resumes a base session (claude -r <id> -p "...") to re-read our project and update documentation. Each morning, developers start an interactive session by forking from that base session (claude -r <id> --fork-session).
The fork correctly inherits all context/knowledge, which is great. However, the old chat messages are rendered in the TUI, cluttering the screen.

Desired behavior
A flag like --no-history or --clean that:

• Forks the session as usual (preserving context for the model)
• But does not render previous messages in the TUI

Workarounds attempted

• clear before launching Claude — TUI re-renders history
• --append-system-prompt — only affects Claude's output, not TUI rendering
• Dropping --fork-session entirely — clean screen but loses session knowledge

Proposed Solution

Add a flag like --clean or --no-history

Alternative Solutions

_No response_

Priority

Medium - Would be very helpful

Feature Category

CLI commands and flags

Use Case Example

We run a nightly cron job that resumes a base session (claude -r <id> -p "...") to re-read our project and update documentation. Each morning, developers start an interactive session by forking from that base session (claude -r <id> --fork-session).
The fork correctly inherits all context/knowledge, which is great. However, the old chat messages are rendered in the TUI, cluttering the screen.

Additional Context

_No response_