Use TypeScript 7 RC side-by-side with TypeScript 6 compatibility

[Copilot]

The repository needed a safe path to evaluate TypeScript 7 RC without disrupting the existing TypeScript 6 toolchain. Microsoft’s compatibility model makes that possible by keeping the 6.x API available under the default package name while exposing the RC compiler through a separate entry point.

• Summary

  • Adopt the TypeScript 6 compatibility package as the default typescript dependency and add a dedicated typescript-7 alias for the RC compiler.
  • Make the project’s compile entry points use the RC compiler explicitly so builds do not depend on ambiguous tsc resolution.

• What changed

  • Updated package.json to use @typescript/typescript6 for typescript and add typescript-7 for typescript@rc.
  • Added a dedicated tsc:7 script that invokes the TypeScript 7 RC binary directly.
  • Routed build, build:check, and build:check-tests through that explicit entry point.

• Example

{
  "devDependencies": {
    "typescript": "npm:@typescript/typescript6@^6.0.0",
    "typescript-7": "npm:typescript@rc"
  }
}

[Copilot]

Pull request overview

This PR introduces a dual-TypeScript setup so the repository can evaluate the TypeScript 7 RC compiler while keeping TypeScript 6 compatibility as the default typescript dependency.

Changes:

• Switch typescript to the TypeScript 6 compatibility package (npm:@typescript/typescript6@^6.0.2) and add a typescript-7 alias for the TypeScript 7 RC compiler.
• Add a dedicated tsc:7 script and route build / build:check / build:check-tests through it.
• Update package-lock.json to reflect the new alias + compatibility dependency graph.

Reviewed changes

Copilot reviewed 1 out of 2 changed files in this pull request and generated 2 comments.

File	Description
package.json	Introduces tsc:7/build scripts and dual TypeScript dependencies (TS6 compatibility + TS7 RC alias).
package-lock.json	Locks the new @typescript/typescript6 and typescript-7 alias dependency trees and platform-specific optional deps for TS7.