Minerva Maldonado, a double-amputee who resides at the West River Health Care Center, joined about 40 of the facility's 100 union employees in a candlelight vigil Tuesday night, as administrators and security guards watched from a distance. HealthBridge, the New Jersey management company that operates the center, locked out employees belonging to the New England Health Care Employees District 1199 a week ago, after nearly a year of negotiations. The company has offered employees a 12 percent raise over three years, but union officials said the proposal also reduces sick and vacation time and allows hiring of per-diem staff, which could reduce the number of employees eligible for benefits.