- CliRequestHandler.MakeError: drop the always-null `hint` parameter and its
`Hint = hint` initializer (none of the 5 call sites pass a hint).
- Cli.UnitTests: consolidate the two per-file ICliOutput test doubles
(RecordingOutput, CaptureOutput) into one shared RecordingCliOutput, removing
duplicated interface-implementation boilerplate.
No behavior change. PowerDisplay.Cli.UnitTests (82) and PowerDisplay.Ipc.UnitTests
(137) pass.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>