refactor(domain): Typed StrategyConfig Value Object - Phase 2

[amodelandme]

Summary

Flag.StrategyConfig was converted from a raw string to a typed StrategyConfig sealed record Value Object. The Flag entity now enforces that config and strategy type are always consistent — a Flag with mismatched strategy type and config shape cannot exist. An IStrategyConfigValidator registry pattern validates raw JSON into typed VOs at the application boundary, and an EF Core Value Converter handles persistence without schema changes.

Changes in this PR

• Typed StrategyConfig VO with ValidatedFor/RawJson and internal trusted constructor
• IStrategyConfigValidator interface + three implementations (None, Percentage, RoleBased)
• StrategyConfigFactory registry dispatch keyed on RolloutStrategy
• Flag constructor/Update/UpdateStrategy enforce config/strategy type match
• EF Core StrategyConfigConverter — no migration needed
• 43 new unit tests (VO, validators, factory, guard clauses)
• All 158 existing unit tests updated and passing
• Skill updates: worktree isolation for /implement, Docs/ casing fix, /git-workflow script automation

Spec

Docs/Decisions/refactor-typed-strategy-config/spec.md

Implementation Notes

Docs/Decisions/refactor-typed-strategy-config/implementation-notes.md

Definition of Done

• StrategyConfig sealed record in Banderas.Domain/ValueObjects/
• internal trusted constructor for EF Core and seed data
• IStrategyConfigValidator interface in Banderas.Domain/Interfaces/
• Three validator implementations in Banderas.Application/Validators/
• StrategyConfigFactory with registry dispatch
• All validators and factory registered in DI
• Flag.StrategyConfig property type is StrategyConfig
• Guard clauses on constructor, Update(), UpdateStrategy()
• Strategies read from flag.StrategyConfig.RawJson
• FlagMappings.ToResponse() maps .RawJson
• BanderasService calls factory before Flag construction/update
• EF Core Value Converter — no migration
• DatabaseSeeder uses valid VOs
• FlagBuilder updated
• 158/158 unit tests passing
• dotnet build -p:TreatWarningsAsErrors=true — 0 warnings
• CSharpier check passes

Testing

dotnet test Banderas.Tests/Banderas.Tests.csproj
dotnet build Banderas.sln -p:TreatWarningsAsErrors=true
dotnet csharpier check .