Separate game responses from native window events

[Krisztiaan]

Summary

• Move paint, right-button release, and mouse-wheel game responses out of the Win32 procedure.
• Keep native message decoding and window validation in the Win32 shell.
• Name the video refresh-rate update for the state it sets, not its native event source.
• Preserve externally visible behavior and compatibility boundaries.

Validation

• uv run --no-project --python 3.13.7 --with-requirements manual/tools/requirements.txt python manual/tools/manage.py update
• uv run --no-project --python 3.13.7 --with-requirements manual/tools/requirements.txt python manual/tools/manage.py check
• Win32 Debug, Win32 Release, and runtime were not run locally; CI covers the supported builds.

Documentation

Added a 0.2.0 internal change record.

[github-actions]

Development builds of 2126839:

• opents-Debug-2272182
• opents-Release-2272182

The links work without a GitHub account. Artifacts expire after 90 days, and this comment follows the latest successful build.