Fix Sophia optimizer shadow generation for ComponentArrays

This fix resolves the issue where Sophia optimizer fails when used with
ComponentArrays and DifferentiationInterface/Enzyme autodiff due to
incorrect shadow type generation.

Problem:
- Line 154 in sophia.jl used `randn(uType, length(θ))` which creates a
  standard Vector, losing the structure of θ when it's a ComponentVector
- This causes MethodError when Enzyme tries to create Duplicated types
  with mismatched structures

Solution:
- Replace with `u = similar(θ); randn!(u)` pattern
- This preserves the structure of θ while filling with random values
- Follows the same pattern used elsewhere in the codebase with `zero(θ)`

References: https://discourse.julialang.org/t/differentiationinterface-not-generating-correct-shadow/131868

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: ChrisRackauckas

src/sophia.jl

@@ -151,7 +151,8 @@ function SciMLBase.__solve(cache::OptimizationCache{
 
             if i % cache.opt.k == 1
                 hₜ₋₁ = copy(hₜ)
-                u = randn(uType, length(θ))
+                u = similar(θ)
+                randn!(u)
                 f.hv(hₜ, θ, u, d)
                 hₜ = βs[2] .* hₜ₋₁ + (1 - βs[2]) .* (u .* hₜ)
             end