Promote v0.2.0-dev.20 folder organization

[Noah8218]

Summary

• Promote v0.2.0-dev.20 responsibility-folder reorganization from the validated Dev main.
• Preserve namespaces, XAML bindings, runtime contracts, deterministic simulation behavior, and add the headless termination diagnostic coverage.
• Keep the public tree free of private proofline records, internal handoff documents, local paths, and test artifacts.

Public-safe scope

• src/** and tests/** changes from Dev commit 49ba4d9252b63ede8f1ef9087576590731eb0ebe.
• OpenVisionLab.MachineStudio.sln, Directory.Build.props, public README.md, and public architecture/version policy documentation.

Verification

• Release solution build with TreatWarningsAsErrors=true: 0 warnings, 0 errors.
• Core 43/43, Vision 31/31, Infrastructure 48/48, Simulation 535/535, MachineStudio 445/445.
• Total: 1,102/1,102 tests passed.

This is a development-candidate version bump. No tag, release publication, or deployment is included.