RelayCommand<int> casts its object parameter directly rather than
converting it, so a string CommandParameter ("7"/"30") would throw
InvalidCastException at runtime. Split into two parameterless commands.
Adds a Usage Monitor modal (Worker menu + wired to the footer/Mission-Control
usage pill's Open command): dynamic gauges built from UsageSnapshotDto.Limits
with gate-threshold marks, a stale/blocked-gate band, and Models/Tasks tabs
backed by GetModelUsageAsync/GetTaskUsageAsync over a 7d/30d/custom range.
mika kuns