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 .ToArray() with collection spread, simplify single-statement
await using blocks, use Lock for Postgres schema gates, and document
IDE0063/IDE0305/IDE0330/CA1859 conventions in csharp-style.md.
Per-player IFactionStandingStore with clamped reads/writes and fail-closed
unknown-faction deny; append-only IReputationDeltaStore; in-memory plus
Postgres V009/V010 when configured. Tests, Bruno health smoke, README.