Add using helper for JS disposable resources

[joshamaju]

Motivation

Add an Effection using helper so JavaScript Disposable and AsyncDisposable values can be scope-owned without requiring the native using keyword.

Approach

• Add lib/using.ts with a using operation that binds disposal to scope teardown.
• Validate disposers at runtime and fail fast for non-disposable values.
• Export using from lib/mod.ts.
• Add test/using.test.ts covering sync and async disposal, teardown on error and halt, async disposal completion, and invalid runtime input.

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/thefrontside/effection@1115

commit: d855861

[cowboyd]

Looks good. We don't have to do this with this PR, but we need a place where we are going to explain this. Maybe in the resources section of the guide?

[joshamaju]

@cowboyd Please check the tests

[taras]

@joshamaju can you rebase and verify the signatures