A tool implementation declares `Effect<Result, Tool.Error>` but a plugin can
fail with any typed error at runtime. Such a failure slipped past every
`catchTag("Tool.Error")" downstream and past classifyToolExits (which drops
Fail reasons on the assumption they are all declines), so the call was never
settled: the part stayed "running" forever, the step continued anyway, and
the execution reported success.
Enforce the declared contract at the untrusted boundary (tool runtime maps
foreign typed failures to Tool.Error) and harden classifyToolExits to surface
any surviving non-decline typed failure as a defect instead of silently
dropping it.
Kit Langton
2fb3d5755f