Cause: validateHost (controllers/hosts.go) wrote a 403 via ReturnError
without aborting, so ControlHost's ctx.IsAborted() check never fired and it
went on to write a second (202) response; the permission was also checked
once per host and not at all for an empty host list.
Fix: validateHost writes no response; it checks host:control once up front
and returns an error, on which ControlHost writes a single 403 and returns.
For "all", the host list is resolved before the one validateHost call.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Rongsong Shen
d720132c8c
