fix: suppress noisy hook lifecycle events

Stop forwarding hook lifecycle events when a project has no configured
.github/hooks/*.json commands so the UI only receives meaningful hook
activity. Also expose the configured-hook state on the bundle, cover the
suppression wiring with tests, and document the updated event semantics.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

sidecar/tests/Aryx.AgentHost.Tests/CopilotWorkflowRunnerTests.cs

@@ -11,6 +11,18 @@ namespace Aryx.AgentHost.Tests;
 
 public sealed class CopilotWorkflowRunnerTests
 {
+    [Fact]
+    public void ConfigureHookLifecycleEventSuppression_SetsStateFromBundle()
+    {
+        RunTurnCommandDto command = CreateApprovalCommand();
+        CopilotTurnExecutionState state = new(command);
+        CopilotAgentBundle bundle = new(Array.Empty<AIAgent>(), hasConfiguredHooks: false);
+
+        CopilotWorkflowRunner.ConfigureHookLifecycleEventSuppression(state, bundle);
+
+        Assert.True(state.SuppressHookLifecycleEvents);
+    }
+
     [Fact]
     public void SelectNewOutputMessages_SkipsFullTranscriptPrefix()
     {