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.
Wire IPositionStateStore to Npgsql when ConnectionStrings:NeonSprawl is set,
with versioned DDL under server/db/migrations and a shared PostgresPositionBootstrap
for schema plus dev-player seeding at host startup. In-memory tests override Postgres
registrations when CI sets the connection string globally.
Add GitHub Actions Postgres service for dotnet test, server README updates,
decomposition and implementation-plan docs, code review write-up, and C# brace
conventions in csharp-style rule.
VinPropane