test: migrate blas/base/dsymv to ULP-based assertions

[Planeshifter]

Resolves a part of #11352.

Description

This pull request migrates the test suite for blas/base/dsymv from relative tolerance testing (EPS-scaled delta comparisons) to ULP (units in the last place) difference testing using @stdlib/assert/is-almost-same-value, per the RFC in #11352.

• Replaces the isApprox helper's rtol/EPS/abs-based tolerance computation in test/test.dsymv.js and test/test.ndarray.js with isAlmostSameValue( actual, expected, ulp ).
• Measures the tightest ULP bound agentically for each of the 8 fixture-driven test cases (row-major/column-major, varying strides, complex access patterns): all 10 isApprox call sites require only ULP = 0 (bit-exact agreement with the fixtures), confirmed deterministic across repeated test runs.

Related Issues

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

Questions

No.

Other

Only the package's test files were changed (test/test.dsymv.js and test/test.ndarray.js); no package.json changes were needed since @stdlib/assert/is-almost-same-value is resolved the same way the previously-used internal packages were. make test TESTS_FILTER=".*/blas/base/dsymv/.*" passes 103/103, run twice to confirm no FMA/architecture flakiness.

Checklist

• Read, understood, and followed the contributing guidelines.

AI Assistance

• Yes

• No

• Code generation (e.g., when writing an implementation or fixing a bug)

• Test/benchmark generation

• Documentation (including examples)

• Research and understanding

Disclosure

This PR was written by Claude Code, including studying prior-art ULP migrations (e.g., blas/base/drotm), converting the test files, and agentically measuring the minimum ULP bound for each test case.

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@stdlib-js/reviewers

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https://claude.ai/code/session_01NMcKyjbbvhSjuJHYWDN12j

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[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
blas/base/dsymv	$\\color{green}470/470$ $\\color{green}+100.00\\%$	$\\color{green}75/75$ $\\color{green}+100.00\\%$	$\\color{green}2/2$ $\\color{green}+100.00\\%$	$\\color{green}470/470$ $\\color{green}+100.00\\%$

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

[Planeshifter]

⚠️ Issue Reference Review

An automated check found potentially unrelated issue/PR references in this PR:

Reference	Assessment	Reasoning
#11352	suspicious	Issue #11352 is an RFC explicitly scoped to migrating math/base/special packages from relative-tolerance to ULP-based testing (its own instructions say to search for a package "in math/base/special"). This PR migrates tests for blas/base/dsymv, which is outside the issue's stated scope.

Why this matters: GitHub automatically closes issues referenced with
closing keywords (Resolves, Closes, Fixes) when the PR is merged. Incorrect
references can accidentally close unrelated issues.

What to do:

• If the reference is correct, no action needed. This check may produce
  false positives.
• If the reference is incorrect, please update your PR description.

This assessment was generated by an AI model and is informational only.

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