The “main player” in the Bronx drug mill that posed as a daycare center — and eventually led to a toddler’s death from fentanyl poisoning — has taken a plea deal that will likely put him behind bars for decades, federal prosecutors announced Monday. Felix Herrera Garcia was initially hit with a federal charge of conspiracy to distribute narcotics resulting in death after four kids under the age of three were poisoned by the drugs he and his compatriots were dealing at Divino Niño Daycare in Kingsbridge. One of the kids — 1-year-old Nicholas Feliz Dominici — died last September...