The schedule trigger fires on every repo where the file exists,
including contributor forks. Forks don't have access to
OPENCODE_WATCH_SLACK_WEBHOOK, so the Slack step fails. The previous
vars.OPENCODE_WATCH_ENABLED guard evaluated to true on forks (empty
!= 'false'), so it didn't protect anything.
Add the same github.repository == 'Kilo-Org/kilocode' guard used by
18 other workflows in this repo.