A capability whose binary launches while the managed runtime hard-fails
(e.g. skill-API mismatch) was reported as `degraded`/ok:true/exit 0, diverging
from plain `gstack doctor` (ok:false/exit 1) for the identical report. Split
the branch so runtime `warn` stays `degraded` and runtime `fail` maps to
`failed`, and add a regression test for the runtime-fail + capability-pass case.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
