Introduce ContractEconomyValidation.TryValidateTemplate and wire it
into TryIssue before persist with economy_cap_exceeded and
invalid_reward_bundle deny codes.
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.
VinPropane