fix(ui): stop tests from polluting the live operation-timing.ndjson

DetailsIsland.BindAsync churn (~1900 binds/day, 91-96% cancelled) was not a
UI reactivity bug: OperationTiming.Shared is a static singleton hardcoded to
~/.todo-app/logs/operation-timing.ndjson, and Ui.Tests/Worker.Tests both
construct real DetailsIslandViewModel/TasksIslandViewModel instances that
call Shared.Record directly. Every dotnet test run appended 50-100 lines
straight into the live app's log — pid-burst analysis showed 13 distinct
test-run pids in the ":?" bucket (tests never pass a source) plus a
no-suffix bucket with no pid field at all (pre-dating the pid-per-line
feature). Real user-driven binds that day: 4.

Made Shared settable and added a [ModuleInitializer]-based TestSetup in
both test projects that redirects it to a per-process temp file before any
test runs.

tests/ClaudeDo.Ui.Tests/TestSetup.cs

@@ -0,0 +1,20 @@
+using System.Runtime.CompilerServices;
+using ClaudeDo.Ui.Services;
+
+namespace ClaudeDo.Ui.Tests;
+
+internal static class TestSetup
+{
+    // Runs once when this test assembly loads, before any test executes. Without it, every test
+    // that constructs a real DetailsIslandViewModel/TasksIslandViewModel/WorkerClient and calls a
+    // method instrumented with OperationTiming.Shared.Record writes straight into the live app's
+    // ~/.todo-app/logs/operation-timing.ndjson — a single Ui.Tests run added 50-100 cancelled
+    // "DetailsIsland.BindAsync:?" lines to that file, dwarfing real usage and making the churn
+    // look like a UI bug.
+    [ModuleInitializer]
+    internal static void RedirectOperationTimingAwayFromRealAppData()
+    {
+        var path = Path.Combine(Path.GetTempPath(), "claudedo-ui-tests", $"operation-timing-{Environment.ProcessId}.ndjson");
+        OperationTiming.Shared = new OperationTiming(path);
+    }
+}