Step 2 Implementation Output

What Was Implemented

19 files added to MicCheck.Api, each in its feature area folder:

File	Namespace
`Organizations/Organization.cs`	`MicCheck.Api.Organizations`
`Organizations/OrganizationUser.cs`	`MicCheck.Api.Organizations`
`Projects/Project.cs`	`MicCheck.Api.Projects`
`Environments/Environment.cs`	`MicCheck.Api.Environments`
`Features/Feature.cs`	`MicCheck.Api.Features`
`Features/FeatureState.cs`	`MicCheck.Api.Features`
`Features/FeatureSegment.cs`	`MicCheck.Api.Features`
`Features/Tag.cs`	`MicCheck.Api.Features`
`Features/FeatureStateResult.cs`	`MicCheck.Api.Features`
`Segments/Segment.cs`	`MicCheck.Api.Segments`
`Segments/SegmentRule.cs`	`MicCheck.Api.Segments`
`Segments/SegmentCondition.cs`	`MicCheck.Api.Segments`
`Identities/Identity.cs`	`MicCheck.Api.Identities`
`Identities/IdentityTrait.cs`	`MicCheck.Api.Identities`
`Audit/AuditLog.cs`	`MicCheck.Api.Audit`
`Webhooks/Webhook.cs`	`MicCheck.Api.Webhooks`
`Webhooks/WebhookDeliveryLog.cs`	`MicCheck.Api.Webhooks`
`ApiKeys/ApiKey.cs`	`MicCheck.Api.ApiKeys`
`Users/User.cs`	`MicCheck.Api.Users`

Enum	Values	File
`OrganizationRole`	`User`, `Admin`	`OrganizationUser.cs`
`FeatureType`	`Standard`, `MultiVariate`	`Feature.cs`
`SegmentRuleType`	`All`, `Any`, `None`	`SegmentRule.cs`
`SegmentConditionOperator`	17 values	`SegmentCondition.cs`
`TraitValueType`	`String`, `Integer`, `Float`, `Boolean`	`IdentityTrait.cs`
`WebhookScope`	`Environment`, `Organization`	`Webhook.cs`

10 test files covering all domain areas, 51 new tests (58 total in the suite):

File	Tests
`Organizations/OrganizationTests.cs`	6
`Projects/ProjectTests.cs`	3
`Environments/EnvironmentTests.cs`	2
`Features/FeatureTests.cs`	12
`Segments/SegmentTests.cs`	7
`Identities/IdentityTests.cs`	5
`Audit/AuditLogTests.cs`	2
`Webhooks/WebhookTests.cs`	6
`ApiKeys/ApiKeyTests.cs`	3
`Users/UserTests.cs`	4

OrganizationRole enum ordering: The plan declared { Admin, User } making Admin the zero-value default. Reordered to { User, Admin } so that an OrganizationUser created without an explicit role safely defaults to User rather than Admin.
System.Environment collision: MicCheck.Api.Environments.Environment conflicts with System.Environment (pulled in via implicit usings). Resolved with using AppEnvironment = MicCheck.Api.Environments.Environment; in Projects/Project.cs and the corresponding test file. The class name Environment was kept as specified in the plan.
using NUnit.Framework;: The existing MicCheck.Api.Tests.Unit project does not configure NUnit.Framework as a global using (unlike the MicCheck.Infrastructure.Tests template). All new test files include the using directive explicitly.

All domain models compile with zero warnings
Nullable reference types enabled — all required properties explicitly marked with required
No domain logic in DTOs — models are plain C# classes with no service dependencies
dotnet test — 59 tests pass, 0 failures