refactor: fold single-consumer helper types into their owners

Consolidate small single-purpose types into the files that own them:
StreamResult into StreamAnalyzer, the Planning context records into
PlanningSessionContext, PrimeClock/PrimeSchedulerOptions into PrimeScheduler,
AgentMcpTools into LifecycleMcpTools, the locator subclasses into
InstallArtifactLocator, LogLineViewModel into DetailsIslandViewModel,
RepoImportItemViewModel into its modal, and StepViewModel into InstallPageViewModel.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/ClaudeDo.Ui/ViewModels/Islands/DetailsIslandViewModel.cs

@@ -13,6 +13,37 @@ using Microsoft.Extensions.DependencyInjection;
 
 namespace ClaudeDo.Ui.ViewModels.Islands;
 
+public enum LogKind { Sys, Tool, Claude, Stdout, Stderr, Done, Msg }
+
+public sealed class LogLineViewModel
+{
+    public required LogKind Kind { get; init; }
+    public required string Text { get; init; }
+    public string TimestampFormatted { get; } = DateTime.Now.ToString("HH:mm:ss");
+    public string KindMarker => Kind switch
+    {
+        LogKind.Sys    => "sys",
+        LogKind.Tool   => "tool",
+        LogKind.Claude => "claude",
+        LogKind.Stdout => "out",
+        LogKind.Stderr => "err",
+        LogKind.Done   => "done",
+        LogKind.Msg    => "claude",
+        _              => "",
+    };
+    public string ClassName => Kind switch
+    {
+        LogKind.Sys    => "log-sys",
+        LogKind.Tool   => "log-tool",
+        LogKind.Claude => "log-claude",
+        LogKind.Stdout => "log-stdout",
+        LogKind.Stderr => "log-stderr",
+        LogKind.Done   => "log-done",
+        LogKind.Msg    => "log-msg",
+        _              => "",
+    };
+}
+
 public sealed partial class DetailsIslandViewModel : ViewModelBase
 {
     private readonly IDbContextFactory<ClaudeDoDbContext> _dbFactory;