test: migrate stats/base/dists/frechet/cdf to ULP-based assertions

[Planeshifter]

Ref: #11352.

Description

What is the purpose of this pull request?

This pull request:

• migrates stats/base/dists/frechet/cdf tests (test.cdf.js, test.factory.js, test.native.js) from EPS-scaled tolerance checks to ULP-based assertions using @stdlib/assert/is-almost-same-value.
• uses a named ULP variable in each fixture test, tightened to the measured minimum over the full fixture set: large alpha (large_shape): 1 ULP (was 10*EPS relative); large s (large_scale): 16 ULP (was 10*EPS relative); large alpha and s (both_large): 5950 ULP (was 4100*EPS relative). Results were deterministic across repeated runs; the native addon test (built locally) passes at the same bounds.

Related Issues

Does this pull request have any related issues?

This pull request has the following related issues:

• [RFC]: Migrate math/base/special packages from relative tolerance testing to ULP difference testing (tracking issue) #11352

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No.

Other

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No.

Checklist

Please ensure the following tasks are completed before submitting this pull request.

• Read, understood, and followed the contributing guidelines.

AI Assistance

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This PR was authored by Claude Code (automated routine), which converted the tests and measured the minimal ULP bounds.

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🤖 Generated with Claude Code

https://claude.ai/code/session_01S8HbpxnDU2cmZZk5k1VXv1

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[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
stats/base/dists/frechet/cdf	$\\color{green}324/324$ $\\color{green}+100.00\\%$	$\\color{green}27/27$ $\\color{green}+100.00\\%$	$\\color{green}4/4$ $\\color{green}+100.00\\%$	$\\color{green}324/324$ $\\color{green}+100.00\\%$

The above coverage report was generated for the changes in this PR.

[kgryte]

The ULP value needs to be inlined.