Add OpenCorporates collector for org targets, gated on an API token

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>

app/Osint/RunnerRegistry.php

@@ -7,6 +7,7 @@ use App\Osint\Runners\DnsRunner;
 use App\Osint\Runners\GravatarRunner;
 use App\Osint\Runners\HoleheRunner;
 use App\Osint\Runners\IpApiRunner;
+use App\Osint\Runners\OpenCorporatesRunner;
 use App\Osint\Runners\SherlockRunner;
 use App\Osint\Runners\TheHarvesterRunner;
 use App\Osint\Runners\WhoisRunner;
@@ -29,11 +30,23 @@ class RunnerRegistry
         'holehe' => HoleheRunner::class,
         'gravatar' => GravatarRunner::class,
         'dns' => DnsRunner::class,
+        'opencorporates' => OpenCorporatesRunner::class,
     ];
 
     public function has(string $sourceKey): bool
     {
-        return isset(self::RUNNERS[$sourceKey]);
+        if (! isset(self::RUNNERS[$sourceKey])) {
+            return false;
+        }
+
+        // OpenCorporates additionally needs an API token configured before
+        // it's actually runnable — otherwise it's hidden rather than shown
+        // as a broken "Run" button that always fails.
+        if ($sourceKey === 'opencorporates') {
+            return filled(config('services.opencorporates.token'));
+        }
+
+        return true;
     }
 
     public function resolve(string $sourceKey): Runner