Publish vite-task-client to npm

[crusty-voidzero]

Summary

We need to publish vite-task-client to npm so tools can consume it as a standalone package.

Context

• vite-task-client is provided by Vite Task and consumed by tools at runtime to tell Vite Task whether to enable cache / what to fingerprint / related runtime metadata.
• It is currently a very thin wrapper with no deps and is type-checked via JSDoc.
• Source: packages/vite-task-client/index.js

Goal

Ship vite-task-client as a published npm package.

Suggested tasks

• Add/verify package metadata needed for npm publish
• Decide whether any build/publish step is required or if direct publish is enough
• Ensure types / exports / files are correct for consumers
• Document install + usage if needed
• Publish an initial version to npm

[Boshen]

@branchseer please let me know when the vite-task-client package is available on the main branch.