Resolves a part of #649.

Description

What is the purpose of this pull request?

This pull request:

• introduces the @stdlib/math/base/special/sinhf package, which computes the hyperbolic sine of a single-precision floating-point number.
• creates the standard package structure including JS implementations, Native C addons (addon.c, main.c), Type definitions, Benchmarks, and Tests.
• implements the initial C wrapper (src/main.c) by following the established pattern used in cosm1f to wrap the double-precision stdlib_base_sinh( x ) and cast the output to a float. I added a TODO comment noting that this should be replaced with a specific single-precision implementation in the future.
• generates comprehensive test fixtures using pure Python to test edge cases, small values, and large values.

Related Issues

Does this pull request have any related issues?

This pull request has the following related issues:

• [RFC]: Add C implementations to base special math functions (tracking issue) #649

Questions

Any questions for reviewers of this pull request?

Since the C implementation currently wraps the double-precision sinh, would you prefer I immediately follow up with a dedicated single-precision algorithm for sinhf in C in a future PR, or is this wrapper sufficient for the time being?

Other

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

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?

• 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.".

I consulted an AI assistant to help me research and understand the stdlib native package structure, specifically how to navigate C addons, bindings, and directory requirements by studying existing packages like cosm1f and sinh.

@stdlib-js/reviewers