Clipboard copy path hard-codes tmux passthrough #25252

Summary

packages/opencode/src/cli/cmd/tui/util/clipboard.ts switches OSC 52 into the tmux DCS passthrough envelope whenever TMUX or STY is present.

That breaks clipboard copy in a common tmux setup:

• set -g set-clipboard on
• set -g allow-passthrough off

In that topology tmux can still handle raw OSC 52 for clipboard forwarding, but the DCS passthrough envelope is exactly what allow-passthrough off blocks.

Reproduction

1. Start tmux with set -g set-clipboard on and set -g allow-passthrough off
2. Run opencode inside tmux over SSH
3. Use any OpenCode-native copy path that goes through Clipboard.copy() (for example a sidebar/message copy action)
4. The terminal clipboard does not update

Current behavior

The helper currently does this when TMUX/STY is set:

const sequence = passthrough ? "\x1bPtmux;\x1b${osc52}\x1b\\" : osc52

Expected behavior

Please support an explicit OSC 52 mode, for example:

• raw
• tmux-passthrough
• off

That would let tmux users keep allow-passthrough off while still using tmux's own set-clipboard on path for raw OSC 52.

Traceability

• Tools used: OpenCode