desktop: make composer Enter / Cmd+Enter behavior configurable #55341

Summary

The desktop app hardcodes the composer key bindings: Enter always submits and Shift+Enter always inserts a newline. There is no setting, and the desktop app does not read the keybinds block from cli.json, so desktop users cannot switch to the Enter = newline / Cmd+Enter = submit layout that the TUI already supports.

Environment

• opencode version: 2.0.28 (desktop app build, [email protected])
• OS: Darwin 27.0.0 (darwin arm64), macOS
• Install/channel: release (downloaded app bundle, /Applications/OpenCode.app)
• Active plugins: none configured

Current Behavior

The composer input handles keydown with a fixed rule:

• Enter (no modifier) → submit
• Shift+Enter → newline
• Cmd/Ctrl+Enter → "alternate" submit, which steers or queues the prompt depending on Settings → General → Follow-up behavior
• Cmd/Ctrl+ArrowUp → edit the first queued prompt

There is no UI to remap any of these. I checked every row registered by the desktop settings screen (settings.general.row.*, settings.appearance.row.*, settings.general.notifications.*, settings.general.sounds.*, settings.timeline.*); there is no keyboard or "Enter key behavior" section.

The TUI already solves this through ~/.config/opencode/cli.json:

{
  "keybinds": {
    "input.submit": "super+return",
    "input.newline": "return"
  }
}

That file is terminal-only and is not read by the desktop app, so the configuration has no effect there.

Reproduction

1. Open OpenCode desktop and start a session.
2. Focus the composer input.
3. Press Enter.
4. The prompt is submitted immediately; a newline cannot be inserted with Enter.
5. Open Settings and look for any keyboard / Enter-key option — none exists.
6. Add the keybinds block above to ~/.config/opencode/cli.json and restart the desktop app — behavior is unchanged.

Expected Behavior

Desktop users should be able to choose how Enter and Cmd/Ctrl+Enter behave in the composer, for example:

• Submit mode (current default): Enter submits, Shift+Enter inserts a newline.
• Newline mode: Enter inserts a newline, Cmd/Ctrl+Enter submits.

Ideally this lives in Settings → General, or the desktop app reads the same keybinds entries that the TUI already uses (input.submit, input.newline) so a single config works across both clients.

Additional Context

• This is a feature request rather than a bug; the current behavior is self-consistent, just not configurable.
• It is consistently reproducible on every launch, not intermittent.
• Workaround: run the TUI via opencode in a terminal, where the existing cli.json keybinds configuration works as expected. Not a good workaround for users who prefer the desktop UI.
• Cmd+Enter is already spoken for by the alternate-submit (steer/queue) action, so a "newline mode" would need to decide how that action is reachable. One option is to keep Cmd+Enter as alternate-submit only while a session is actively running, and as plain submit when idle.
• Verified by inspecting the shipped bundle (/Applications/OpenCode.app/Contents/Resources/app.asar), build [email protected]. No private paths, tokens, or project data are included here.