fix: support windows cmd shims in fork mode

[UrielAbel]

Q	A
Bug fix?	yes
New feature?	no
BC breaks?	no
Deprecations?	no
Tests pass?	yes
Fixed tickets	#5991, #5871
License	MIT
Doc PR	https://github.com/pm2-hive/pm2-hive.github.io/pulls

Add detection for .cmd / .bat targets on Windows in forkMode.

When pm_exec_path is a Windows shim (e.g. npm.cmd), run it via shell with no Node interpreter, instead of trying to load it as JavaScript.

On Windows, commands like script: "npm" or exec_interpreter: "none" combined with pm_exec_path pointing to npm.cmd caused PM2 to spawn node npm.cmd, leading Node to parse the .cmd file as JS and crash with a syntax error.

[CLAassistant]

All committers have signed the CLA.

[jack-dev-crypto]

Hi, thanks for this PR.
I’ve been running into the same issue on Windows when using PM2 to run npm scripts.
Just to confirm — does this change fully address the cmd shim spawning problem on Windows?
In other words, should pm2 start npm -- start work reliably now?
Appreciate the work on this.

[UrielAbel]

Exactly, this change resolves all known cases where the Windows cmd shim is spawned incorrectly.
I’ve been using this version in my own setup for some time now, and it has been working reliably for me.

Thank you for the response.