feat(cli): delegate multiple global installs to npm

[liangmiQwQ]

Summary

• Add a batch-aware global install path for multiple vp install -g package specs.
• Route vp update -g package batches through the same path so npm handles the install work in one process.
• Keep managed package metadata, binary conflict checks, shim creation, and the existing npm-prefix package layout after the batch install completes.

Why

Multiple global package installs previously resolved Node and spawned npm install -g once per package. Delegating the package list to one npm invocation lets npm handle its own parallel download and extraction work while Vite+ performs the managed-store commit afterward.

Resolves #1476

Validation

• cargo test -p vite_global_cli global_install -- --nocapture
• git diff --check

Note: cargo test -p vite_global_cli currently aborts in tests::unknown_argument_detected_with_pass_as_value_hint with a stack overflow; the same failure reproduces when running that single test directly.

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