Violent crime has created a grim new normal in Big Apple subway stations — the platform wallflower. Skittish straphangers are steering clear of the edge — and pinning their backs to the wall as they await their train, terrified they’ll become the next victim of a random shove onto the tracks, riders told The Post. On two afternoons recently, The Post witnessed hundreds of riders hugging the walls inside stations at East 86th, East 77th, East 68th, East 59th and East 51st streets, and West 18th Street, 14th Street-Union Square, and Wall Street.