fix(clipboard): write OSC52 to /dev/tty instead of stdout

packages/opencode/src/cli/cmd/tui/util/clipboard.ts

@@ -4,19 +4,34 @@ import clipboardy from "clipboardy"
 import { lazy } from "../../../../util/lazy.js"
 import { tmpdir } from "os"
 import path from "path"
+import fs from "fs"
 
 /**
  * Writes text to clipboard via OSC 52 escape sequence.
  * This allows clipboard operations to work over SSH by having
  * the terminal emulator handle the clipboard locally.
+ *
+ * Writes to /dev/tty directly to bypass terminal multiplexers
+ * (Zellij, tmux, screen) that intercept OSC52 on stdout.
  */
 function writeOsc52(text: string): void {
   if (!process.stdout.isTTY) return
   const base64 = Buffer.from(text).toString("base64")
   const osc52 = `\x1b]52;c;${base64}\x07`
   const passthrough = process.env["TMUX"] || process.env["STY"]
   const sequence = passthrough ? `\x1bPtmux;\x1b${osc52}\x1b\\` : osc52
-  process.stdout.write(sequence)
+
+  // Write to /dev/tty directly to bypass terminal multiplexers.
+  // SSH_TTY is set when connected via SSH, otherwise use /dev/tty.
+  const ttyPath = process.env["SSH_TTY"] || "/dev/tty"
+  try {
+    const fd = fs.openSync(ttyPath, "w")
+    fs.writeSync(fd, sequence)
+    fs.closeSync(fd)
+  } catch {
+    // Fallback to stdout if /dev/tty is unavailable (e.g., Windows)
+    process.stdout.write(sequence)
+  }
 }
 
 export namespace Clipboard {