Krikri::PluginArchUnsupportedError
Issue #1 (arch awareness) - raised when a remote target reports a CPU architecture this controller's plugin binaries were not built for and no binaries for that architecture exist next to the running executable. Deliberately its own exception class rather than a plain Exception (or a transport failure): the batch pre-upload pass and the per-task paths both special-case it into one clean, actionable fatal ("no aarch64 plugin binaries ...") instead of the exec-format failure the uploaded binary would otherwise produce on the target, and instead of being misbooked as UNREACHABLE (the host is reachable
- the controller just has nothing it can run on it).