Refactor build steps into component interfaces

.fallout/build.schema.json

@@ -38,7 +38,6 @@
         "References",
         "ReportCoverage",
         "Restore",
-        "RunTargetInDockerImageTest",
         "Test",
         "UpdateContributors",
         "UpdateStargazers"

build/Build.cs

@@ -30,7 +30,14 @@ partial class Build
         ITest,
         IReportCoverage,
         IPublish,
-        ICreateGitHubRelease
+        ICreateGitHubRelease,
+        // Build-local steps (build/Steps/) — each concern is its own component.
+        IGenerateTools,
+        IGeneratePublicApi,
+        IDownloadLicenses,
+        IHandleExternalRepositories,
+        IUpdateContributors,
+        IUpdateStargazers
 {
     public static int Main() => Execute<Build>(x => ((IPack)x).Pack);
 
@@ -70,7 +77,6 @@ partial class Build
     string MajorMinorPatchVersion => Major
         ? $"{ParseMajor(ThisAssembly.AssemblyInformationalVersion) + 1}.0.0"
         : ThisAssembly.AssemblyInformationalVersion.Split('+')[0];
-    string MilestoneTitle => $"v{MajorMinorPatchVersion}";
 
     static int ParseMajor(string informationalVersion)
         => int.Parse(informationalVersion.Split('.')[0]);

build/Steps/IDownloadLicenses.cs

@@ -0,0 +1,45 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using Fallout.Common;
+using Fallout.Common.IO;
+using Fallout.Components;
+using Serilog;
+using static Fallout.Common.IO.HttpTasks;
+
+// Step: fetch the third-party licenses bundled into the packages. Hooks into Pack via
+// DependentFor<IPack> so it runs as part of the default pipeline, not just on demand.
+interface IDownloadLicenses : IFalloutBuild
+{
+    AbsolutePath LicensesDirectory => TemporaryDirectory / "licenses";
+
+    IEnumerable<(string Project, string Url)> Licenses
+        => new[]
+           {
+               ("Glob", "https://raw.githubusercontent.com/kthompson/glob/develop/LICENSE"),
+               ("ICSharpCode.SharpZipLib", "https://raw.githubusercontent.com/icsharpcode/SharpZipLib/master/LICENSE.txt"),
+               ("Microsoft.Build", "https://raw.githubusercontent.com/dotnet/msbuild/main/LICENSE"),
+               ("Microsoft.CodeAnalysis", "https://raw.githubusercontent.com/dotnet/roslyn/main/License.txt"),
+               ("Newtonsoft.Json", "https://raw.githubusercontent.com/JamesNK/Newtonsoft.Json/master/LICENSE.md"),
+               ("NuGet", "https://raw.githubusercontent.com/NuGet/NuGet.Client/dev/LICENSE.txt"),
+               ("Octokit", "https://raw.githubusercontent.com/octokit/octokit.net/main/LICENSE.txt"),
+               ("Serilog", "https://raw.githubusercontent.com/serilog/serilog/dev/LICENSE"),
+               ("Spectre.Console", "https://raw.githubusercontent.com/spectreconsole/spectre.console/main/LICENSE.md"),
+               ("YamlDotNet", "https://raw.githubusercontent.com/aaubry/YamlDotNet/master/LICENSE.txt")
+           };
+
+    Target DownloadLicenses => _ => _
+        .After<ICompile>()
+        .DependentFor<IPack>()
+        .Executes(() =>
+        {
+            LicensesDirectory.CreateOrCleanDirectory();
+
+            var downloadTasks = Licenses.Select(async x =>
+            {
+                await HttpDownloadFileAsync(x.Url, LicensesDirectory / $"{x.Project}.txt");
+                Log.Information("Downloaded license for {Project}", x.Project);
+            });
+            Task.WaitAll(downloadTasks.ToArray());
+        });
+}