SimulationMetaData: use typed float defaults and add typed keyword constructor

[AhmedSalih3d]

Motivation

• Ensure float-like defaults in SimulationMetaData are explicitly typed to the FloatType parameter to avoid unintended promotion or ambiguity.
• Allow users to construct SimulationMetaData{D,T,...} with Real literals (e.g., Float64) while coercing numeric fields to the declared T to make typed usage ergonomic and safer.

Description

• Replace float-like default literals with typed forms: OutputEach = FloatType(0.02), CurrentTimeStep/TotalTime/SimulationTime = zero(FloatType), and TimeSteps = FloatType[] in src/SimulationMetaDataConfiguration.jl.
• Add an outer keyword constructor SimulationMetaData{D,T,S,K,B,L}(; kwargs...) that validates allowed keyword names, preserves non-numeric fields, and converts numeric scalar and vector metadata fields to T using ConvertMetaDataFloat helpers.
• Provide ConvertMetaDataFloat inline helpers to convert Real scalars and vectors into the target floating type T while leaving other values untouched.
• Add tests in test/runtests.jl (SimulationMetaData Float32 keyword conversion) that construct SimulationMetaData{2,Float32} from Float64 literals and assert that OutputEach, OutputTimes, CurrentTimeStep, TotalTime, SimulationTime, TimeSteps, and Δx use Float32.

Testing

• Ran a quick runtime check with julia --project=. -e 'using SPHExample; m=SimulationMetaData{2,Float32}(SimulationName="x",SaveLocation=".",OutputEach=0.05,OutputTimes=[0.05,0.1],CurrentTimeStep=0.001,TotalTime=1.0,SimulationTime=2.0,TimeSteps=[0.001,0.002],Δx=0.01); @show typeof(m) typeof(m.OutputEach) typeof(m.OutputTimes) typeof(m.TimeSteps) typeof(m.Δx); m2=SimulationMetaData{2,Float32}(SimulationName="x",SaveLocation=".",OutputTimes=0.2); @show typeof(m2.OutputTimes) typeof(m2.TimeSteps)' which showed the fields were converted to Float32 as expected.
• Ran the full test suite with julia --project=. -e 'using Pkg; Pkg.test()', which errored in a pre-existing time stepping test due to MethodError: no method matching Δt(..., ::SimulationConstants{Float64}, ::SPHKernelInstance{...}) before the new metadata tests executed.
• Added the unit test SimulationMetaData Float32 keyword conversion to test/runtests.jl; the manual checks above confirm the constructor behavior passes for the exercised cases.

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