feat: add u as alias for update command

[Ausoj]

Summary

Adds u as a short alias for the update command, making it consistent with i for install.

Motivation

npm i is the canonical short form for npm install — the most commonly used npm command. However, npm update lacks an equivalent single-character alias. The existing npm up alias works, but feels inconsistent compared to i.

Adding u makes the CLI more ergonomic and intuitive:

npm i    # install   ✅ already exists
npm u    # update    ✅ this PR

Changes

• Added u: 'update' alias in lib/utils/cmd-list.js, grouped alongside the existing up: 'update' alias

Notes

• u is not currently used by any other alias or command, so there is no conflict
• Follows the same pattern as other single-character aliases (i, r, t, c, s, v, x)

[ItsAMirko]

I would love that. Always running in the same problem and would really like to have that additional shortcut.

[arnemileswinter]

second this, a mitigation to RSI as well.

[owlstronaut]

I'm not sure about this. My brain tells me npm u means uninstall. I don't think the u is unambiguous enough to add it here. I find the existing r equally misleading, but we're already here.

[KevinExtremo]

I think this is a great idea! I love using the shorthands.

I also do not believe that the argument about u standing for uninstall to be a counter. Uninstall is a destructive action while the other shorthands are constructive actions.

I understand one could argue that an update can change contracts but to me its not the same as a full on removal.

So in that sense I am actually happy that uninstall does not come with a shorthand.

[larsmenzel]

Actually a regular thing I run into. Seems like a neat addition which wouldn't hurt to add :)