Wrap OverrideInitData functions in FWW for type erasure

[ChrisRackauckas-Claude]

Summary

• Wraps the function-typed fields inside OverrideInitData with FunctionWrappersWrapper during promote_f, erasing per-model RuntimeGeneratedFunction types:
  • NonlinearFunction.f in initializeprob (IIP, concrete arg types)
  • initializeprobmap (OOP, Any-typed args)
  • initializeprobpmap (OOP, Any-typed args)
• Models with the same state/parameter structure now reuse compiled solver code through initialization, reducing TTFX from ~4s to <1s per additional model

Benchmark (MTK + Rodas5P, 4 models)

Model	FullSpecialize	AutoSpecialize (before)	AutoSpecialize (after)
M1 (LV 2D, 2p)	5.5s	4.7s	4.8s
M2 (Brus 2D, 2p)	4.2s	3.7s	0.8s
M3 (VdP 2D, 1p)	4.0s	3.7s	3.8s
M4 (Rob 3D, 3p)	4.8s	3.7s	3.8s

M2 benefits fully because it shares the same MTKParameters type as M1 (same number of states and params). M3/M4 still recompile because their MTKParameters types differ.

Test plan

• DiffEqBase core tests pass locally

🤖 Generated with Claude Code

[ChrisRackauckas-Claude]

Closing — the Union{Nothing, OverrideInitData} abstract typing in unwrapped_f (SciMLBase) already handles the type erasure for initialization data. No need to wrap the individual functions inside OverrideInitData.