Bumps csproj, yaml, repo.json, CHANGELOG, ROADMAP and README in
lock-step to 1.5.4. Forge-post DE-body added with the Polish & Motion
versionsnatur. Slim-rule applied to the yaml and repo.json changelog
blocks (keeps v1.5.4 + v1.5.3 + v1.5.2 + v1.5.1, drops v1.5.0).
A csharpier reflow of two v1.5.4 source files (ChatLogWindow,
HellionStyle) is folded in. preflight.sh blocks A-F all green.
