chore: add build state tracking to internal context

[chenjiahan]

Summary

Track build status and errors in the internal context to provide better build state visibility. This is the basis for subsequent improvements to browser logs and assets middleware.

Checklist

• Tests updated (or not required).
• Documentation updated (or not required).

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[Copilot]

Pull Request Overview

This PR adds build state tracking to the internal context to provide better visibility into the build status and error state. The changes introduce new types for tracking build status and integrate build state updates throughout the compilation lifecycle.

• Introduces new BuildStatus and BuildState types to track compilation state
• Adds build state tracking to the internal context with initialization
• Updates compiler hooks to maintain build status and error state throughout the compilation process

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
packages/core/src/types/context.ts	Defines new build state types and adds buildState property to InternalContext
packages/core/src/createContext.ts	Initializes buildState with default idle status and no errors
packages/core/src/provider/createCompiler.ts	Integrates build state updates into compiler lifecycle hooks

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