Prevent `npm` calls for projects that use other package managers

[liangmiQwQ]

Description

Currently, Vite+ allows npm runs in a project using other package managers, even if we mark like "packageManager": "pnpm@10.33.2".

We can take a look at corepack's behavior, which will print an error and stop users from running other an incompatible package manager.

% pnpm i                                
This project is configured to use npm because /Users/liangmi/code/npm/cli/package.json has a "packageManager" field

Suggested solution

We've already merged #1629, similar to it, we could also add a check logic, if the Vite+ detects this project is using other pms, we can print a similar error and prevent users running it.

Additional context

In addition, for npm version management, Vite+ takes over corepack's duty, so I believe it is very meaningful to add it.