The working-directory service throws WorkingDirectoryError:
WORKING_DIRECTORY_INVALID for an empty cd, WORKING_DIRECTORY_NOT_FOUND
for a missing target, and WORKING_DIRECTORY_UNAVAILABLE when the
current and original directories are both gone or the service was
disposed. The working_directory tool reports a missing Agent as
ToolContextUnavailableError and an empty cd as ToolArgsError.
sandbox-policy reports a session cwd it cannot use as a workspace root
as SandboxInvalidRootError (SANDBOX_INVALID_ROOT), whose constructor
now names the role of the rejected path.
Refs #7869
sjw1231
45db11970c