There’s finally a way to snag a man in uniform before Valentine’s Day. First responders and other public employees now have their own dating app to help them find a partner who truly understands the demands and unpredictability of a public-service job. Secure, designed exclusively for public servants — from cops, firefighters and TSA agents to doctors, nurses and 911 dispatchers — launched in August and already has close to 1,000 users. The Post spoke to two who have already met matches. Queens