Enable rendered public API docs QA

[ChrisRackauckas-Claude]

Ignore this PR until reviewed by @ChrisRackauckas.

Summary

• enable SciMLTesting rendered public API docs QA
• keep DEQs as a targeted rendered ignore because it is a module-valued alias already documented in prose on the API page and Documenter canonicalizes its @docs entry to the module binding

Validation

• git diff --check passed
• Runic v1.7.0 on test/qa/qa.jl passed
• Direct QA on Julia +1.10 passed: Quality Assurance | 17 pass, 17 total; doctests passed 1 pass
• Default Pkg.test() on Julia +1.10 was attempted with timeout 3600; it timed out during Pkg.precompile before reaching test/runtests.jl

No [sources] or path source entries were added.

[ChrisRackauckas-Claude]

CI note: the GPU lane failure is outside this one-file QA change. The failed job is tests / GPU (julia 1, self-hosted Linux X64 gpu gpu-v100), with the final summary Layers Tests | 734 pass, 36 error, 770 total; the errors are all in the CUDA DEQ convolution-shaped (3, 3, 1, 3) cases across solver/model variants.

The rendered public API docs QA path passes locally on Julia +1.10: Quality Assurance | 17 pass, 17 total, and doctests pass. I did not change tests or backend behavior for this PR.

[ChrisRackauckas-Claude]

Current red check is not rendered-docs/QA. The failing job is tests / GPU, with repeated cuDNN convolution execution errors in test/layers_tests.jl for x_size: (3, 3, 1, 3):

CUDNNError: CUDNN_STATUS_EXECUTION_FAILED_CUDART (code 5003)

Summary from the GPU job: DEQ | 540 pass, 36 error, 576 total; Multiscale DEQ | 194 pass, 194 total.

I did not change code here because that is a GPU/cuDNN behavioral failure, not docs/docstrings/rendered public API coverage. Documentation is still in progress on the current poll.