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.
Replace placeholder XP level math with content-backed thresholds validated in CI and at server boot, and update docs/manual QA/review artifacts to reflect NEO-39 delivery and follow-up fixes.