Closes the last coverage gap for org (person remains intentionally
unaddressed — no good free/non-scraping option exists). Unlike the
other 8 sources, OpenCorporates now requires an API token even on its
free tier (confirmed: keyless request gets 401). RunnerRegistry::has()
checks services.opencorporates.token is configured before exposing the
source as runnable, so it degrades to "not yet integrated" in the UI
rather than a broken Run button, until OPENCORPORATES_API_TOKEN is set.
Also fixes a real bug hit while building this: a RunnerRegistry::REQUIRES
class constant mapping source key to a closure crashed on file load
(PHP class constants can't hold closures) — inlined the one check
instead of building an abstraction for a single case.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
