Add Thunk.force and use it in wf jrunscript tests

[davidpcaldwell]

Summary

• add $api.fp.Thunk.force as a minimal thunk evaluator (Thunk<T> -> T)
• add Fifty definition and test coverage for Thunk.force
• update wf test.jrunscript flow in wf.js to use Thunk.force in the pipeline

Validation

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[Copilot]

Pull request overview

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This PR adds a minimal thunk evaluator ($api.fp.Thunk.force) to the functional utilities and uses it to simplify the wf test.jrunscript flow by evaluating the produced thunk directly in the $api.fp.now(...) pipeline.

Changes:

• Add $api.fp.Thunk.force(thunk) => thunk() to loader/$api-Function.js.
• Extend the Fifty definitions/tests to cover Thunk.force.
• Refactor wf.js’s test.jrunscript implementation to use Thunk.force in the pipeline instead of storing and calling an intermediate thunk.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
wf.js	Refactors the jrunscript test runner to evaluate the thunk via $api.fp.Thunk.force within the existing $api.fp.now pipeline.
loader/$api-Function.js	Introduces Thunk.force as a minimal thunk evaluator.
loader/$api-Function.fifty.ts	Adds Thunk.force to the exported typings and includes Fifty test coverage validating repeated evaluation.