/memory silently fails with nvim as $EDITOR

/memory prints "Opened memory file" but nvim never appears. System vim works fine.

Root cause: The cy() function (editor opener for /memory) uses execaCommandSync with a string command, while pb8() (Ctrl+G editor) uses spawnSync with a proper args array. execaCommandSync doesn't work correctly with nvim in this context.

Fix: Change cy() to use spawnSync directly, matching how pb8() already does it. Confirmed fix works by patching cli.js v2.1.83.

Also, cy() silently swallows errors and /memory reports "Opened" regardless of whether the editor actually launched.

Environment: macOS arm64, tmux, nvim v0.11.3, Claude Code v2.1.83