Add Holehe collector for email targets

Closes the email target-type gap (previously had zero collectors).
Checks whether an email is registered on 120+ sites via the
password-reset-oracle technique. Shares the Sherlock/whois venv.

HoleheRunner gates success on the CSV file existing rather than the
process exit code: holehe's CLI calls Python's exit("message") right
after writing results on its normal success path, which always yields
exit code 1 regardless of outcome — discovered while verifying this
end-to-end against the real dev server and queue worker.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

app/Providers/AppServiceProvider.php

@@ -29,5 +29,6 @@ class AppServiceProvider extends ServiceProvider
         RateLimiter::for('osint-runner:whois', fn () => Limit::perMinute(20));
         RateLimiter::for('osint-runner:sherlock', fn () => Limit::perMinute(10));
         RateLimiter::for('osint-runner:theharvester', fn () => Limit::perMinute(5));
+        RateLimiter::for('osint-runner:holehe', fn () => Limit::perMinute(15));
     }
 }