fix(cli) Linux clipboard selection

[bornmw]

Linux clipboard selection support (fixes #29963)

Issue for this PR

Closes #29963

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

When I select text in Linux terminal it is expected that it's copied to PRIMARY buffer and I can paste it with a mouse middle button click. Opencode only copies to Clipboard (pasted with Ctrl-V).
Added a config option to selected between Clipboard / Primary / Both (default) and added additional calls to xclip and others.
I implemented Promise.allSettled to update both buffers in parallel

How did you verify your code works?

I select text and selection goes to the configured destination - Clipboard / Primary / Both (default)

Screenshots / recordings

there's no way to record a video that would show difference between pasting via Ctrl-V and middle button click

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR

If you do not follow this template your PR will be automatically rejected.

[github-actions]

Hey! Your PR title Linux clipboard selection doesn't follow conventional commit format.

Please update it to start with one of:

• feat: or feat(scope): new feature
• fix: or fix(scope): bug fix
• docs: or docs(scope): documentation changes
• chore: or chore(scope): maintenance tasks
• refactor: or refactor(scope): code refactoring
• test: or test(scope): adding or updating tests

Where scope is the package name (e.g., app, desktop, opencode).

See CONTRIBUTING.md for details.

[github-actions]

The following comment was made by an LLM, it may be inaccurate:

Potential Duplicate PRs Found

1. PR fix: enable primary clipboard copy for Wayland/X11 to fix Linux middle-click paste #6370: "fix: enable primary clipboard copy for Wayland/X11 to fix Linux middle-click paste"

   • fix: enable primary clipboard copy for Wayland/X11 to fix Linux middle-click paste #6370
   • Directly addresses PRIMARY clipboard support for Linux middle-click paste, which is the core feature of PR fix(cli) Linux clipboard selection #32370

2. PR fix(tui): prevent false clipboard copy success on Linux #31252: "fix(tui): prevent false clipboard copy success on Linux"

   • fix(tui): prevent false clipboard copy success on Linux #31252
   • Related to Linux clipboard handling and validation

3. PR fix(opencode): report clipboard copy failures #27861: "fix(opencode): report clipboard copy failures"

   • fix(opencode): report clipboard copy failures #27861
   • Related to clipboard copy error handling on Linux

Note: PR #6370 appears to be the most relevant, as it specifically addresses enabling PRIMARY clipboard copy for Linux middle-click paste functionality—the exact feature being implemented in PR #32370.

[bornmw]

The following comment was made by an LLM, it may be inaccurate:

Potential Duplicate PRs Found

I reviewed the potential duplicates flagged by the bot, and here is how this PR compares:

PR #31252 and PR #27861 are not duplicates. They handle clipboard failure reporting and error validation rather than the primary selection buffer.

PR #6370 attempts to solve the same underlying issue (adding PRIMARY selection for Linux middle-click paste), but there are a few key differences. First, that PR has been stalled since December. Second, my implementation introduces a more flexible configuration approach—letting the user explicitly choose between Clipboard, Primary, or Both (defaulting to Both)—whereas #6370 uses a simple boolean toggle. Finally, this PR optimizes the copy operation under the hood by utilizing Promise.allSettled to update the buffers in parallel.

Given these architectural differences and the inactivity on #6370, I believe this PR provides a more robust and complete solution to closing #29963. Let me know if any changes are needed!