Add AutoDespecialize parameter policy

[ChrisRackauckas-Claude]

What changed

Adds AutoDespecialize as a specialization policy distinct from both the unchanged AutoSpecialize policy and the constrained AutoRespecialize policy. Supporting solvers can use it to place arbitrary parameter objects behind the existing DespecializedParameters dynamic function barrier, while transformations can opt out through unwrap_parameters.

The new public marker is documented and included in the specialization preference allowlist. This is a minor public API addition, so the package version advances to 3.46.0.

Verification

Before this commit, the public marker discriminator failed:

$ julia +release --project=. -e 'using SciMLBase; @assert SciMLBase.AutoDespecialize <: SciMLBase.AbstractSpecialization'
ERROR: UndefVarError: `AutoDespecialize` not defined in `SciMLBase`

After this commit:

$ julia +release --project=. -e 'using SciMLBase; @assert SciMLBase.AutoDespecialize <: SciMLBase.AbstractSpecialization; @assert SciMLBase.AutoSpecialize !== SciMLBase.AutoDespecialize; @assert SciMLBase.AutoRespecialize !== SciMLBase.AutoDespecialize; println("AutoDespecialize marker: pass")'
AutoDespecialize marker: pass

$ GROUP=Core julia +release --project=. -e 'using Pkg; Pkg.test()'
Despecialized Parameters | 42 passed
Public interface checks | 552 passed
Remake | 4430 passed
Testing SciMLBase tests passed

$ GROUP=QA julia +release --project=. -e 'using Pkg; Pkg.test()'
QA | 51 passed | 51 total
Testing SciMLBase tests passed

The exact docs build on current master reaches CheckDocument and then fails only on the 16 pre-existing Problem_Traits HTTP 403 links. With the focused existing fix from #1485 stacked locally, the same command completes doctests, cross-references, rendering, and link checking with exit 0:

$ julia +release --project=docs docs/make.jl
[ Info: RenderDocument: rendering document.
[ Info: HTMLWriter: rendering HTML pages.
[ Info: Automatic `version="3.46.0"` for inventory from ../Project.toml

Runic 1.7, typos over the changed files, and git diff --check all exit 0.

Not verified here

Solver-side automatic wrapping and precompilation are intentionally separate changes in DiffEqBase/OrdinaryDiffEq. ModelingToolkit's default selection and parameter-interface forwarding are also separate so each ownership boundary remains independently reviewable.

Draft: ignore until reviewed by @ChrisRackauckas.

Links

• Existing clean-base docs fix: Fix stable problem-trait documentation links #1485
• Existing dynamic barrier implementation: Add dynamic parameter despecialization for all SciML functions #1511
• Existing constrained-policy rename: Rename parameter respecialization marker #1510
• ModelingToolkit integration draft: Default MTK problems to AutoDespecialize ModelingToolkit.jl#4919