Default settings applied to every command run through the DI-resolved `IProcessRunner`, configured with `AddProcessKit(Action<ProcessKitOptions>)` or bound from an `IConfiguration` section. Each default is applied **only when the command does not set it itself** — a per-command `Timeout` or working directory always wins over the default here. Every property is optional (a `null` / no-value leaves the corresponding behaviour unchanged), so an unconfigured `AddProcessKit()` behaves exactly as before. These are the defaults a *primitive* runner can apply; for verb-layer defaults (retry) and richer per-tool defaults (encoding, ok-codes, environment), register a named client with `AddProcessKitClient` — its template carries them into the command before a verb runs.

`IServiceCollection.AddProcessKit()` / `AddProcessKitClient()` / `AddProcessKitGroup()` extensions.