release(v1.5.4): manifest bump and forge post

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.

HellionChat/Ui/ChatLogWindow.cs

@@ -515,8 +515,7 @@ public sealed class ChatLogWindow : Window
                             $"{theme.Name}##quick-theme-{theme.Slug}",
                             isActive,
                             ImGuiSelectableFlags.DontClosePopups
-                        )
-                        && !isActive
+                        ) && !isActive
                     )
                         Plugin.ThemeRegistry.Switch(theme.Slug);
                 }
@@ -547,8 +546,7 @@ public sealed class ChatLogWindow : Window
                             $"{tabs[i].Name}##quick-tab-{i}",
                             isActive,
                             ImGuiSelectableFlags.DontClosePopups
-                        )
-                        && !isActive
+                        ) && !isActive
                     )
                         ChangeTab(i);
                 }