test: migrate stats/base/dists/levy/logpdf to ULP-based assertions

[Planeshifter]

Resolves a part of #11352.

Description

What is the purpose of this pull request?

This pull request:

• migrates the fixture-based value tests for stats/base/dists/levy/logpdf from relative-tolerance (delta/tol) comparisons to ULP-based assertions using @stdlib/assert/is-almost-same-value, per the tracking issue [RFC]: Migrate math/base/special packages from relative tolerance testing to ULP difference testing (tracking issue) #11352.
• updates test/test.logpdf.js, test/test.factory.js, and test/test.native.js.
• the tightest ULP bound was determined agentically by running the full fixture suite; the measured minimum required bound was 0 ULP (i.e., exact bit-for-bit agreement) across all three fixture sets (positive_mean, negative_mean, large_variance) in every test body, matching the precedent set in already-converted, same-family packages such as stats/base/dists/uniform/logpdf.
• pre-existing edge-case skip guards (e.g., expected[i] === 0.0 && y < EPS in the JS tests, expected[i] === NINF && y === NINF in the native tests) were left untouched, since they guard against known JS-vs-C divergence at specific fixture points rather than being part of the tolerance idiom being migrated.
• the now-unused abs (and, where applicable, EPS) requires were removed accordingly.

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

Questions

Any questions for reviewers of this pull request?

No.

Other

Any other information relevant to this pull request? This may include screenshots, references, and/or implementation notes.

Full fixture suite (test.js, test.logpdf.js, test.factory.js) run twice at the final ULP bound to confirm determinism; all assertions passed both times. test.native.js is skipped locally (no built native addon in this environment) but was updated to mirror the same idiom.

Checklist

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

• Read, understood, and followed the contributing guidelines.

AI Assistance

When authoring the changes proposed in this PR, did you use any kind of AI assistance?

• Yes
• No

If you answered "yes" above, how did you use AI assistance?

• Code generation (e.g., when writing an implementation or fixing a bug)
• Test/benchmark generation
• Documentation (including examples)
• Research and understanding

Disclosure

If you answered "yes" to using AI assistance, please provide a short disclosure indicating how you used AI assistance. This helps reviewers determine how much scrutiny to apply when reviewing your contribution. Example disclosures: "This PR was written primarily by Claude Code." or "I consulted ChatGPT to understand the codebase, but the proposed changes were fully authored manually by myself.".

This PR was authored by Claude Code, run as an automated, scheduled task on behalf of the repository maintainer (@Planeshifter) to work through the ULP migration tracking issue (#11352) package by package, following the pattern established by prior merged PRs against this same issue.

---

@stdlib-js/reviewers

---

Generated by Claude Code

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
stats/base/dists/levy/logpdf	$\\color{green}291/291$ $\\color{green}+0.00\\%$	$\\color{green}23/23$ $\\color{green}+0.00\\%$	$\\color{green}4/4$ $\\color{green}+0.00\\%$	$\\color{green}291/291$ $\\color{green}+0.00\\%$

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