[Bug] Screen not rendered after external editor (Ctrl+G) exits in tmux

Bug Description
● ## Bug: Screen not rendered after returning from Ctrl+G external editor (nvim)

### Description
After pressing Ctrl+G to open nvim as external editor, then closing nvim, the Claude Code screen becomes
blank/invisible. The text is not rendered and Ctrl+L does not recover it.

### Environment

• Claude Code: 2.1.72
• Terminal: Ghostty 1.3.0 (GTK, Linux)
• Shell: zsh inside tmux
• tmux: default-terminal "tmux-256color"
• TERM: xterm-256color
• EDITOR: nvim
• Neovim: v0.11.6
• OS: Ubuntu (Linux 6.17.0-14-generic)
• Local environment (not SSH)

### Steps to Reproduce

1. Run Claude Code inside tmux on Ghostty
2. Press Ctrl+G to open external editor (nvim)
3. Edit or just close nvim (:q)
4. Return to Claude Code

### Expected Behavior
Claude Code UI should be fully restored and visible.

### Actual Behavior
Screen is blank/empty. Text is not rendered. Ctrl+L does not fix it. Only restarting Claude Code recovers the UI.

### Additional Context

• tmux config uses allow-passthrough all and set-clipboard on
• Ghostty config is mostly default (font + keybinds only)
• This appears to be an alternate screen buffer restoration issue after the external editor process exits

Environment Info

• Platform: linux
• Terminal: tmux
• Version: 2.1.72
• Feedback ID: 11e56375-13b5-4e7c-9cf7-f8f71522ca9f

Errors

[{"error":"Error: NON-FATAL: Lock acquisition failed for /home/jh/.local/share/claude/versions/2.1.72 (expected in multi-process scenarios)\n    at Rv$ (/$bunfs/root/src/entrypoints/cli.js:2611:2025)\n    at ERA (/$bunfs/root/src/entrypoints/cli.js:2611:1169)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-03-10T07:04:03.959Z"}]