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.
