feat: add C implementation for stats/base/dists/erlang/pdf

[rautelaKamal]

Ref #3575.

Description

What is the purpose of this pull request?

This pull request:

• Adds a C implementation for @stdlib/stats/base/dists/erlang/pdf, fulfilling the open RFC [RFC]: Add C implementation for @stdlib/stats/base/dists/erlang/pdf #3575.
• Validates that the shape parameter k is a non-negative integer using stdlib_base_is_nonnegative_integer(k).
• Reuses the existing Gamma distribution implementation by safely proxying the evaluation directly to the stdlib_base_dists_gamma_pdf C function, since the Erlang distribution is mathematically a special case of the Gamma distribution.
• Integrates standard N-API bindings, Makefile, include.gypi, binding.gyp, and the native.js benchmarks & tests.

Related Issues

Does this pull request have any related issues?

This pull request has the following related issues:

• [RFC]: Add C implementation for @stdlib/stats/base/dists/erlang/pdf #3575

Questions

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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

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

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• 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.".

I utilized an AI coding assistant to help scaffold the C implementations, N-API bindings, makefiles, and native benchmarks. The logic was reviewed and verified manually to ensure mathematical correctness and alignment with standard project practices.

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@stdlib-js/reviewers

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
stats/base/dists/erlang/pdf	$\color{green}289/289$ $\color{green}+100.00%$	$\color{green}11/11$ $\color{green}+100.00%$	$\color{green}3/3$ $\color{green}+100.00%$	$\color{green}289/289$ $\color{green}+100.00%$

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

[Om-A-osc]

@rautelaKamal
CI checks failing for package.json.
Order of keys is important for package.json linting. Maybe have a look at lib/node_modules/@stdlib/stats/base/dists/erlang/mean/package.json and try rearranging.