hermes - 💡(How to fix) Fix CLI terminal resize triggers slow full-history re-render on long conversations

Problem

When using the classic CLI (non --tui mode), any terminal resize or window move triggers a visible full-conversation re-render. For long conversations (50+ messages) this takes several seconds, making the terminal feel unresponsive. Users perceive it as "reloading everything from scratch."

Root Cause

The _recover_after_resize() mechanism in cli.py replays the full output history as an ANSI payload after SIGWINCH. While it batches into a single prompt_toolkit print, the amount of data grows linearly with conversation length — sessions with 50+ messages replay hundreds of terminal lines. Cursor state recovery then syncs the full scrollback, causing the delay.

Steps to Reproduce

1. Start hermes (classic CLI)
2. Have a conversation with 20+ exchanges
3. Drag the terminal window to resize it, or switch to a different terminal tab and back
4. Observe full conversation text reappearing and sluggish response

Expected Behavior

Resizing should be instant and invisible:

1. Preserve existing terminal scrollback — only re-render the input prompt/footer area to match the new width
2. If full redraw is unavoidable, complete in <100ms regardless of conversation length
3. Terminal tab switches should not cause visible re-rendering

Suggested Approaches

1. Preserve scrollback — on resize, only redraw the input prompt line + status bar instead of replaying the entire conversation history
2. Lazy replay — show a brief status message during resize and defer full UI restoration until the next user interaction
3. Better debounce — increase debounce delay and cancel stale redraws during resize storms

Environment

• Hermes Agent 0.14.0
• macOS (Terminal.app / iTerm2)
• Classic CLI mode (not --tui)