[ChrisRackauckas-Claude]

Ignore until reviewed by @ChrisRackauckas.

Summary

• migrate package and QA environments to SciMLTesting 2.4 with plain strict run_qa
• replace private Serialization and deepcopy hooks with public APIs; serialized dropped functions now fail explicitly, requiring a 0.6.0 release
• add definition-site SciMLStyle API docs, rendered public/setup docs, doctests, export checks, and generic Function interface coverage

Verification

• Julia 1.12: Pkg.test() passed
• Julia 1.10: Pkg.test() passed
• strict run_qa(RuntimeGeneratedFunctions): 20/20 passed
• Documenter doctests, rendered docs, linkcheck, and checkdocs = :exports: passed
• Runic and git diff --check: passed