Faced with a mounting budget shortfall, AC Transit officials discussed plans last night to drastically reduce bus services for East Bay Area residents. Among plans on the chopping block: an end to about half of all weekend bus routes, an end to overnight service on many lines, and the privatization of paratransit services for the elderly and the disabled. AC Transit officials say severe cuts are inevitable after the union representing bus drivers and mechanics refused to accept a new labor contract. Sabrina Jacobs reports from Oakland.