Added @UseGuards(AuthGuard) and rate limiting (@Throttle) to
/api/v1/federation/identity/verify endpoint. Configured strict
rate limit (10 req/min) to prevent abuse of this previously
public endpoint. Added test to verify guards are applied.
Security improvement: Prevents unauthorized access and rate limit
abuse of identity verification endpoint.
Fixes#290
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>