BUG(tui): Ctrl+Z (terminal_suspend) broken on Windows -- SIGTSTP is not a valid signal

[mynameistito]

Description

Ctrl+Z is mapped to terminal_suspend by default. The handler at app.tsx:647-655 calls process.kill(0, "SIGTSTP"), which is a POSIX-only signal. On Windows this throws or silently fails, and renderer.suspend() runs but the process never actually suspends. The terminal gets left in a broken state with no way back.

There's also a misleading tip at tips.tsx:151 that tells Windows users to "Press Ctrl+Z to suspend the terminal and return to your shell", which doesn't work.

I tested on both the latest Windows Terminal and Windows Terminal Preview on Windows 11, OpenCode v1.3.3.

There's an existing PR (#16120) that adds an early return on win32, making Ctrl+Z a no-op. I think it'd be better to call exit() instead, since that's the closest thing to "get me back to my shell" on a platform without job control. The exit() function is already in scope and handles renderer cleanup, buffer flushing, and the Ctrl+C guard teardown.

Two files, roughly 8-10 lines:

1. packages/opencode/src/cli/cmd/tui/app.tsx (~line 647): add a process.platform === "win32" check, call exit() on Windows instead of renderer.suspend() + SIGTSTP
2. packages/opencode/src/cli/cmd/tui/component/tips.tsx (line 151): conditionally hide the Ctrl+Z tip on Windows

Related: #16050, #6517, PR #16120

Plugins

Not relevant

OpenCode version

1.3.3

Steps to reproduce

1. Launch opencode on Windows 11
2. Press Ctrl+Z
3. The terminal breaks or the app throws

Screenshot and/or share link

2026-03-27.13-06-40.mp4

Operating System

Windows 11

Terminal

Windows Terminal, Windows Terminal Preview

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• no way to recover from an accidental ctrl+z in windows #16050: Same issue — Ctrl+Z broken/unrecoverable on Windows
• Rider TUI - Ctrl+Z uses EOF - unable to return to session #6517: Same issue — Ctrl+Z leaves terminal in broken state on Windows

For keybind-related issues, please also check our pinned keybinds documentation: #4997

[whws007]

This bug makes opencode unusable on Windows when accidentally pressing Ctrl+Z. It's been open for weeks. Can we get a fix soon?
This should be a simple fix - just ignore the EOF character (Ctrl+Z / ASCII 26) in the TUI input layer instead of treating it as end of input.