Bug: OPENCODE_EXPERIMENTAL_DISABLE_COPY_ON_SELECT clears selection on Ctrl/Cmd+C instead of copying

[astron8t-voyagerx]

Description

When OPENCODE_EXPERIMENTAL_DISABLE_COPY_ON_SELECT=true, drag-selecting text and then pressing Ctrl/Cmd+C does not copy — it clears the selection. On macOS the keyboard shortcut never copies; on terminals using the Kitty Keyboard Protocol (Ghostty, Kitty, WezTerm), Cmd+C reaches the app but is silently swallowed.

Root cause is in packages/opencode/src/cli/cmd/tui/util/selection.ts:

• handleSelectionKey only matches event.ctrl && event.name === "c". It does not handle event.meta (xterm modifier 32) or event.super (Kitty Keyboard Protocol modifier bit 8, which is what macOS Cmd maps to in fromKittyMods).
• When the match fails and the focused renderable has no inner selection, the function falls through to renderer.clearSelection(), actively wiping the highlight.

Note: opencode enables Kitty Keyboard Protocol explicitly (useKittyKeyboard: {} in app.tsx), so on supporting terminals Cmd+C does reach the app — it's just not recognized.

This is a follow-up bug to PR #4996 (which introduced the flag). Reports of the same behavior live in the #4751 thread (andy-blum's Scenario 2, mhrf's note that Ctrl+C works in Ghostty but Cmd+C does not).

Steps to reproduce

1. OPENCODE_EXPERIMENTAL_DISABLE_COPY_ON_SELECT=true opencode in Ghostty on macOS
2. Drag-select any text in the TUI
3. Press Cmd+C
4. Expected: text copied to clipboard, selection cleared by the copy action
5. Actual: nothing copied, selection wiped without copying

Operating System

macOS 26 (Darwin 25.4.0)

OpenCode version

1.14.48

[github-actions]

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

[github-actions]

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