Authorities ruled yesterday that the death of a 30-year-old Brighton woman was a homicide. Edinalva da Silva’s body was found inside her Cummings Road apartment Wednesday afternoon, but she might have been laying dead there for up to three weeks, police said. An autopsy indicated that she died as a result of blunt force trauma. Anyone with information is asked to contact the Homicide Unit at 617-343-4470. Information can be left anonymously by calling the CrimeStoppers Tip Line at 800-494-TIPS or by texting the word TIP to CRIME (27463).