refactor(arch)!: Application ring — core API → Fallout.Application (onion step 2)

CHANGELOG.md

@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - **Onion layering — namespace realignment begun; `Fallout.Core` → `Fallout.Domain`** ([ADR-0006](docs/adr/0006-onion-layering-and-namespace-realignment.md)). First ring of a project-wide realignment to explicit onion layers (`Fallout.Domain` / `Fallout.Application` / `Fallout.Infrastructure`, `Fallout.Cli` composition root) with `namespace = project = layer`, dissolving the `Fallout.Common.*` catch-all. This entry covers **step 1 (the Domain ring)**; the Application/Infrastructure/tooling-port rings land on `experimental` as separate PRs (any that miss the 2026 cut roll to 2027).
   - **Namespaces**: `Fallout.Core.Planning` → `Fallout.Domain.Planning`; `ITargetModel` and `ExecutionStatus` move out of `Fallout.Common.Execution` → `Fallout.Domain.Execution`. **Package/assembly**: `Fallout.Core` → `Fallout.Domain`. Replace the corresponding `using` directives and any `PackageReference`/`ProjectReference`.
   - **Migration / shim**: the `Nuke.*` transition shims silently stop re-exporting the two moved types (the generator only mirrors the `Fallout.Common.*` prefix). A fresh migration/shim strategy is designed once the realignment completes (ADR-0006 defers it deliberately); native `Fallout.*` consumers rewrite the two `using`s above.
+  - **Step 2 (the Application ring)**: the core API `Fallout.Build` declared under `Fallout.Common.*` — `FalloutBuild`, `Target`, `[Parameter]` & attributes, `Host`, the execution engine, value injection, and the CI ports — moves to **`Fallout.Application.*`**. Native consumers rewrite `using Fallout.Common;` → `using Fallout.Application;` (and the `Fallout.Common.Execution`/`.CI`/`.ValueInjection` sub-namespaces likewise). Performed by a semantic rewriter (`tools/OnionRewriter`). The `Nuke.*` shim surface that mirrored these (`Nuke.Common.Target`, `…Parameter`, …) lapses for now — `Nuke.Consumer` and `Nuke.Common.Shim.Tests` are temporarily out of the solution until the migration phase. The `Fallout.Build` **assembly/project** is renamed to `Fallout.Application` in a later mechanical step (namespaces are already migrated).
 - **Adopted calendar versioning (`YYYY.MINOR.PATCH`) + dual-pace channel model; retired the v11 numbering** ([ADR-0004](docs/adr/0004-calendar-versioning-and-dual-pace-channels.md)). Fallout now ships on calendar versions (`2026.0.0`, `2026.1.0`, …) — mechanically valid SemVer with the major equal to the calendar year. **Breaking changes are batched to the yearly major cut**; mid-year stable releases (`release/YYYY`) are strictly non-breaking. `main` becomes the published **edge** channel (date-stamped prereleases to GitHub Packages); the slow/stable track lives on `release/YYYY`. Opt-in unstable APIs are marked `[Experimental("FALLOUT0xx")]`.
   - **Migration / impact**: the `11.0.x` packages never shipped a clean stable release (all unlisted), so this strands no stable consumers. The headline content previously slated for "v11" now ships as **`2026.0.0`**. Any tooling pinned to a `[11.0,12.0)`-style range should retarget the `2026.x` line.
   - **Legacy unaffected**: the `release/v10` line stays on semver `10.x` and continues to receive security/critical fixes — v10 consumers do nothing.

build/Build.CodeGeneration.cs

@@ -1,11 +1,11 @@
-using System;
-using Fallout.Common;
+using System;
 using Fallout.Common.IO;
 using Fallout.Common.Tools.GitHub;
 using Fallout.Common.Utilities.Collections;
 using static Fallout.CodeGeneration.CodeGenerator;
 using static Fallout.CodeGeneration.ReferenceUpdater;
 using static Fallout.Common.Tools.Git.GitTasks;
+using Fallout.Application;
 
 partial class Build
 {

build/Build.Contributors.cs

@@ -5,6 +5,7 @@
 using Fallout.Common.Utilities;
 using Fallout.Common.Utilities.Collections;
 using static Fallout.Common.Tools.Git.GitTasks;
+using Fallout.Application;
 
 partial class Build
 {

build/Build.GlobalSolution.cs

@@ -2,15 +2,15 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using Fallout.Common;
-using Fallout.Common.Git;
 using Fallout.Common.IO;
 using Fallout.Solutions;
 using Fallout.Common.Tools.GitHub;
 using Fallout.Common.Utilities;
 using Fallout.Utilities.Text.Yaml;
-using static Fallout.Common.ControlFlow;
+using static Fallout.Application.ControlFlow;
 using static Fallout.Common.Tools.Git.GitTasks;
+using Fallout.Application;
+using Fallout.Application.Git;
 
 partial class Build
 {

build/Build.Licenses.cs

@@ -1,11 +1,11 @@
-using Fallout.Common;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
 using Fallout.Common.IO;
 using Fallout.Components;
 using Serilog;
 using static Fallout.Common.IO.HttpTasks;
+using Fallout.Application;
 
 partial class Build
 {

build/Build.PublicApi.cs

@@ -6,6 +6,7 @@
 using Fallout.Common.IO;
 using Fallout.Common.Utilities;
 using Fallout.Common.Utilities.Collections;
+using Fallout.Application;
 
 partial class Build
 {

build/Build.RunTargetInDockerTest.cs

@@ -3,6 +3,7 @@
 using Fallout.Common.Tools.Docker;
 using Fallout.Common.Utilities;
 using Serilog;
+using Fallout.Application;
 
 partial class Build
 {

build/Build.Stargazers.cs

@@ -1,9 +1,9 @@
-using System.Linq;
+using System.Linq;
 using System.Threading.Tasks;
-using Fallout.Common;
 using Fallout.Common.IO;
 using Fallout.Common.Tools.GitHub;
 using Fallout.Common.Utilities;
+using Fallout.Application;
 
 partial class Build
 {

build/Build.Terminal.cs

@@ -1,7 +1,7 @@
-using System;
+using System;
 using System.Linq;
-using Fallout.Common;
-using Fallout.Common.Execution;
+using Fallout.Application.Execution;
+using Fallout.Application;
 
 [DisableDefaultOutput<Terminal>(
     DefaultOutput.Logo,

build/Build.cs

@@ -3,19 +3,20 @@
 using System.Linq;
 using NuGet.Packaging;
 using Fallout.Common;
-using Fallout.Common.CI;
 using Fallout.Common.CI.GitHubActions;
-using Fallout.Common.Execution;
-using Fallout.Common.Git;
 using Fallout.Common.IO;
 using Fallout.Solutions;
 using Fallout.Common.Tooling;
 using Fallout.Common.Tools.DotNet;
 using Fallout.Common.Tools.GitHub;
 using Fallout.Common.Utilities;
 using Fallout.Components;
-using static Fallout.Common.ControlFlow;
+using static Fallout.Application.ControlFlow;
 using static Fallout.Common.Tools.DotNet.DotNetTasks;
+using Fallout.Application;
+using Fallout.Application.CI;
+using Fallout.Application.Git;
+using Fallout.Application.Execution;
 
 [DotNetVerbosityMapping]
 [ShutdownDotNetAfterServerBuild]

fallout.slnx

@@ -41,13 +41,15 @@
   <Project Path="tests\Fallout.Cli.Tests\Fallout.Cli.Tests.csproj" />
   <Project Path="tests\Fallout.Migrate.Tests\Fallout.Migrate.Tests.csproj" />
   <Project Path="tests\Fallout.Migrate.Analyzers.Tests\Fallout.Migrate.Analyzers.Tests.csproj" />
-  <Project Path="tests\Nuke.Common.Shim.Tests\Nuke.Common.Shim.Tests.csproj" />
+  <!-- Temporarily excluded during the onion realignment (ADR-0006): these exercise the Nuke.* shim
+       surface, which lapses while the rings land. Re-added when the migration/shim strategy is
+       redesigned for the final shape. -->
   <Project Path="tests\Nuke.Components.Shim.Tests\Nuke.Components.Shim.Tests.csproj" />
   <Project Path="tests\Fallout.ProjectModel.Tests\Fallout.ProjectModel.Tests.csproj" />
   <Project Path="tests\Fallout.Solution.Tests\Fallout.Solution.Tests.csproj" />
   <Project Path="tests\Fallout.SourceGenerators.Tests\Fallout.SourceGenerators.Tests.csproj" />
   <Project Path="tests\Benchmarks\Fallout.Persistence.Solution.Benchmarks\Fallout.Persistence.Solution.Benchmarks.csproj" />
-  <Project Path="tests\Consumers\Nuke.Consumer\Nuke.Consumer.csproj" />
+  <!-- Nuke.Consumer excluded during the onion realignment (ADR-0006) — consumes the lapsing Nuke.* shim. -->
   <Project Path="tests\Consumers\Fallout.Consumer.Local\Fallout.Consumer.Local.csproj" />
   <Project Path="tests\Consumers\Fallout.Consumer.NuGet\Fallout.Consumer.NuGet.csproj" />
   <Project Path="tests\Fallout.Tooling.Tests\Fallout.Tooling.Tests.csproj" />

src/Fallout.Build/Attributes/ArgumentsFromGitCommitMessageAttribute.cs

@@ -1,12 +1,14 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Linq;
-using Fallout.Common.CI;
-using Fallout.Common.Git;
 using Fallout.Common.Tooling;
 using Fallout.Common.Utilities;
+using Fallout.Application.CI;
+using Fallout.Application.Git;
+using Fallout.Application;
+using Fallout.Common;
 
-namespace Fallout.Common.Execution;
+namespace Fallout.Application.Execution;
 
 public class ArgumentsFromGitCommitMessageAttribute : BuildExtensionAttributeBase, IOnBuildCreated
 {

src/Fallout.Build/Attributes/DisableDefaultOutputAttribute.cs

@@ -1,7 +1,7 @@
-using System;
+using System;
 using System.Linq;
 
-namespace Fallout.Common;
+namespace Fallout.Application;
 
 [AttributeUsage(AttributeTargets.Class)]
 public class DisableDefaultOutputAttribute : Attribute

src/Fallout.Build/Attributes/ShutdownDotNetAfterServerBuildAttribute.cs

@@ -1,9 +1,9 @@
 using System;
 using System.Linq;
-using Fallout.Common.Execution;
 using Fallout.Common.Tooling;
+using Fallout.Application.Execution;
 
-namespace Fallout.Common.CI;
+namespace Fallout.Application.CI;
 
 /// <summary>
 ///   See <a href="https://github.com/dotnet/cli/issues/11424">dotnet/cli#11424</a>.

src/Fallout.Build/Attributes/UnsetVisualStudioEnvironmentVariablesAttribute.cs

@@ -3,7 +3,7 @@
 using System.Linq;
 using Fallout.Common.Utilities.Collections;
 
-namespace Fallout.Common.Execution;
+namespace Fallout.Application.Execution;
 
 public class UnsetVisualStudioEnvironmentVariablesAttribute : BuildExtensionAttributeBase, IOnBuildCreated
 {

src/Fallout.Build/Attributes/VerbosityMappingAttribute.cs

@@ -1,10 +1,13 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using Fallout.Common.Execution;
 using Fallout.Common.Utilities.Collections;
+using Fallout.Application.Execution;
+using Fallout.Application;
+using Fallout.Common;
+using Fallout.Common.Tooling;
 
-namespace Fallout.Common.Tooling;
+namespace Fallout.Application.Tooling;
 
 public class VerbosityMappingAttribute : BuildExtensionAttributeBase, IOnBuildInitialized
 {

src/Fallout.Build/CICD/BuildServerConfigurationGeneration.cs

@@ -1,7 +1,8 @@
 using System;
 using System.Linq;
+using Fallout.Application;
 
-namespace Fallout.Common.CI;
+namespace Fallout.Application.CI;
 
 public static class BuildServerConfigurationGeneration
 {

src/Fallout.Build/CICD/BuildServerConfigurationGenerationAttributeBase.cs

@@ -1,11 +1,12 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
-using Fallout.Common.Execution;
 using Fallout.Common.Utilities.Collections;
+using Fallout.Application.Execution;
+using Fallout.Application;
 
-namespace Fallout.Common.CI;
+namespace Fallout.Application.CI;
 
 public class BuildServerConfigurationGenerationAttributeBase : BuildExtensionAttributeBase
 {

src/Fallout.Build/CICD/CIAttribute.cs

@@ -1,10 +1,12 @@
-using System;
+using System;
 using System.Linq;
 using System.Reflection;
 using Fallout.Common.Utilities;
-using Fallout.Common.ValueInjection;
+using Fallout.Application.ValueInjection;
+using Fallout.Application;
+using Fallout.Common;
 
-namespace Fallout.Common.CI;
+namespace Fallout.Application.CI;
 
 [AttributeUsage(AttributeTargets.Class | AttributeTargets.Field | AttributeTargets.Property)]
 public class CIAttribute : ValueInjectionAttributeBase

src/Fallout.Build/CICD/ChainedConfigurationAttributeBase.cs

@@ -1,10 +1,11 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using Fallout.Common.Execution;
 using Fallout.Common.Utilities.Collections;
+using Fallout.Application.Execution;
+using Fallout.Common;
 
-namespace Fallout.Common.CI;
+namespace Fallout.Application.CI;
 
 public abstract class ChainedConfigurationAttributeBase : ConfigurationAttributeBase
 {

src/Fallout.Build/CICD/ConfigurationAttributeBase.cs

@@ -2,12 +2,14 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using Fallout.Common.Execution;
 using Fallout.Common.IO;
 using Fallout.Common.Utilities;
-using static Fallout.Common.CI.BuildServerConfigurationGeneration;
+using static Fallout.Application.CI.BuildServerConfigurationGeneration;
+using Fallout.Application;
+using Fallout.Application.Utilities;
+using Fallout.Application.Execution;
 
-namespace Fallout.Common.CI;
+namespace Fallout.Application.CI;
 
 [AttributeUsage(AttributeTargets.Class)]
 public abstract class ConfigurationAttributeBase : Attribute, IConfigurationGenerator

src/Fallout.Build/CICD/ConfigurationEntity.cs

@@ -1,8 +1,8 @@
 using System;
 using System.Linq;
-using Fallout.Common.Utilities;
+using Fallout.Application.Utilities;
 
-namespace Fallout.Common.CI;
+namespace Fallout.Application.CI;
 
 public abstract class ConfigurationEntity
 {

src/Fallout.Build/CICD/CustomFileWriter.cs

@@ -1,8 +1,9 @@
 using System;
 using System.IO;
 using System.Linq;
+using Fallout.Common.Utilities;
 
-namespace Fallout.Common.Utilities;
+namespace Fallout.Application.Utilities;
 
 public class CustomFileWriter
 {

src/Fallout.Build/CICD/GenerateBuildServerConfigurationsAttribute.cs

@@ -1,11 +1,13 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using Fallout.Common.Execution;
 using Fallout.Common.Utilities.Collections;
-using static Fallout.Common.CI.BuildServerConfigurationGeneration;
+using static Fallout.Application.CI.BuildServerConfigurationGeneration;
+using Fallout.Application.Execution;
+using Fallout.Application;
+using Fallout.Common;
 
-namespace Fallout.Common.CI;
+namespace Fallout.Application.CI;
 
 public class GenerateBuildServerConfigurationsAttribute
     : BuildServerConfigurationGenerationAttributeBase, IOnBuildCreated

src/Fallout.Build/CICD/IBuildServer.cs

@@ -1,5 +1,5 @@
-
-namespace Fallout.Common.CI;
+
+namespace Fallout.Application.CI;
 
 public interface IBuildServer
 {

src/Fallout.Build/CICD/IConfigurationGenerator.cs

@@ -1,10 +1,10 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using Fallout.Common.Execution;
 using Fallout.Common.IO;
+using Fallout.Application.Execution;
 
-namespace Fallout.Common.CI;
+namespace Fallout.Application.CI;
 
 public interface IConfigurationGenerator
 {

src/Fallout.Build/CICD/InvokeBuildServerConfigurationGenerationAttribute.cs

@@ -1,13 +1,14 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Linq;
-using Fallout.Common.Execution;
 using Fallout.Common.IO;
 using Fallout.Common.Tooling;
 using Serilog;
-using static Fallout.Common.CI.BuildServerConfigurationGeneration;
+using static Fallout.Application.CI.BuildServerConfigurationGeneration;
+using Fallout.Application.Execution;
+using Fallout.Application;
 
-namespace Fallout.Common.CI;
+namespace Fallout.Application.CI;
 
 public class InvokeBuildServerConfigurationGenerationAttribute
     : BuildServerConfigurationGenerationAttributeBase, IOnBuildCreated

src/Fallout.Build/CICD/NoConvertAttribute.cs

@@ -1,7 +1,7 @@
-using System;
+using System;
 using System.Linq;
 
-namespace Fallout.Common.CI;
+namespace Fallout.Application.CI;
 
 [AttributeUsage(AttributeTargets.Property)]
 public class NoConvertAttribute : Attribute

src/Fallout.Build/CICD/Partition.cs

@@ -4,7 +4,7 @@
 using System.Globalization;
 using System.Linq;
 
-namespace Fallout.Common.CI;
+namespace Fallout.Application.CI;
 
 [TypeConverter(typeof(TypeConverter))]
 public class Partition

src/Fallout.Build/CICD/PartitionAttribute.cs

@@ -1,8 +1,9 @@
 using System;
 using System.Linq;
 using System.Reflection;
+using Fallout.Application;
 
-namespace Fallout.Common.CI;
+namespace Fallout.Application.CI;
 
 public class PartitionAttribute : ParameterAttribute
 {