Apply Roslyn/dotnet-format fixes across NeonSprawl.Server and
NeonSprawl.Server.Tests: collection expressions, concrete helper
return types, record XML docs, logging guards, quest store refactors,
and removal of redundant usings via GlobalUsings.cs. Extend
csharp-style.md with the recurring patterns.
Fix the hotbar client test transport body construction so the suite parses and runs again, and normalize AAA marker ordering in the flagged C# tests to restore readability consistency with the test template.
Audit all test files and bring them in line with formatting/style expectations by adding explicit AAA markers across server test methods and fixing GDScript test lint/format issues.