Parlyn Engine v0.5.0 Beta 15 (unsigned)

Parlyn Engine v0.5.0 Beta 15

This unsigned Windows beta adds Ground Placement for the current
selection through a toolbar command and the End key. Placement uses the
rendered object bounds and integrates with multi-selection, Undo/Redo
and scene persistence. Automatic Surface Snap remains a later step.
The portable ZIP creates no Windows installation or uninstall entry and
remains the preferred unsigned test path.

Important: This beta is unsigned and may be blocked by Windows
Smart App Control. Download it only from this official release, verify
the published SHA-256 checksum, and do not bypass a Windows security
decision. It must not be described as trusted, digitally signed,
SignPath-signed or Foundation-certified.

The repository provides reproducible packaging, required checks,
documented maintainer acceptance and SHA-256 verification. A public
code-signing identity may be added later when operationally justified
and sustainably funded. This release is not signed by SignPath or any
other public certificate provider.

Maintainer acceptance instructions:
https://github.com/WebCrew/Parlyn-Engine/blob/main/docs/MAINTAINER-ACCEPTANCE-v0.5.0-beta.15.md