copyToClipboard() reports success even when the copy actually failed

[aakashrajput]

What's broken

copyToClipboard() in src/screens/repl.ts:803-815 always returns true unless the spawnSync call itself throws — it never checks the exit status or error field of the result:

function copyToClipboard(text: string): boolean {
  try {
    if (process.platform === "darwin") {
      spawnSync("pbcopy", [], { input: text, encoding: "utf-8" });
    } else if (process.platform === "win32") {
      spawnSync("clip", [], { input: text, encoding: "utf-8", shell: true });
    } else {
      const r = spawnSync("xclip", ["-selection", "clipboard"], { input: text, encoding: "utf-8" });
      if (r.error) spawnSync("xsel", ["--clipboard", "--input"], { input: text, encoding: "utf-8" });
    }
    return true;   // <-- always true, even if xclip AND xsel are both missing
  } catch { return false; }
}

On a Linux box with neither xclip nor xsel installed, both spawn calls fail silently (non-zero exit / ENOENT), but the function still returns true. Every caller (/copy command, "copy last response", clipboard menu actions) then shows "Copied to clipboard." when nothing was copied.

Suggested fix

Check the actual result before returning success:

const r1 = spawnSync("xclip", ["-selection", "clipboard"], { input: text, encoding: "utf-8" });
if (!r1.error && r1.status === 0) return true;
const r2 = spawnSync("xsel", ["--clipboard", "--input"], { input: text, encoding: "utf-8" });
return !r2.error && r2.status === 0;

Same pattern for the darwin/win32 branches (pbcopy/clip — check status === 0 before returning true).

Acceptance criteria

• Returns false when the platform clipboard tool is missing or exits non-zero.
• Existing successful-copy behavior unchanged on macOS/Windows/Linux-with-xclip.
• A test or two covering the failure path (mock spawnSync to return a non-zero status / error).

[Ayush7614]

Hi @aakashrajput — PR for this: #48