Single quotes in `concurrently` commands work on Unix shells but not on
Windows Command Shell (`cmd.exe`), causing the `INPUT` environment
variable to not be set and npm scripts to fail with errors like:
'cross-env' is not recognized as an internal or external command
Error: INPUT environment variable is not set
Replace single quotes with escaped double quotes (`\"`) in npm scripts
in all example `package.json` files.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
27196b3b05