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

[Copilot]

TypeScript 7 RC can be evaluated without displacing existing TypeScript 6-based tooling. This change adopts the recommended npm-alias approach so the project can run TypeScript 7 RC alongside the TypeScript 6 compatibility package while keeping builds on the RC compiler.

• Overview

  • Adds a side-by-side TypeScript setup using @typescript/typescript6 as the default typescript dependency and a typescript-7 alias for the RC compiler.
  • Updates the build entrypoint to invoke the TypeScript 7 RC compiler directly.

• Dependency shape

  {
    "devDependencies": {
      "typescript": "npm:@typescript/typescript6@^6.0.2",
      "typescript-7": "npm:typescript@rc"
    }
  }

• Build behavior

  • Preserves compatibility for tools that still rely on TypeScript 6 while allowing this project to compile with the TypeScript 7 RC toolchain explicitly.

[Copilot]

Pull request overview

This PR updates the project’s TypeScript toolchain to evaluate TypeScript 7 RC without displacing TypeScript 6 consumers, using npm aliasing so TS6 remains available as the typescript dependency while builds explicitly compile with the TS7 RC compiler.

Changes:

• Aliases typescript to npm:@typescript/typescript6 and adds typescript-7 as npm:typescript@rc.
• Updates the build script to invoke the TypeScript 7 RC tsc entrypoint directly.
• Updates package-lock.json to reflect the new alias dependency graph (including TS7 platform optional deps).

Reviewed changes

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

File	Description
package.json	Adds TS6/TS7 side-by-side devDependencies and switches the build script to TS7 RC.
package-lock.json	Locks the npm-alias TypeScript resolution and brings in TS7 RC optional platform packages.

[pethers]

@copilot investigate and fix

Test and Report / prepare (pull_request)
Test and Report / prepare (pull_request)Failing after 41s
Test and Report Latest Node / prepare (pull_request)
Test and Report Latest Node / prepare (pull_request)Failing after 50s

invoking wrong version should support at 26 at least

[Copilot]

@copilot investigate and fix

Test and Report / prepare (pull_request)
...

I fixed the install failure by correcting the TypeScript alias dependency metadata in package.json so npm can parse and install the side-by-side TS6/TS7 setup correctly. I also verified the build and test flow locally under Node 26, including npm run build and the unit test suite.