I know it’s a bit of a hike for you, but Longfellow has a Spanish immersion program. It’s K-8. It’s part of San Diego Unified and in the Clairemont area.
Birney Elementary has Mandarin immersion. It feeds into PB Middle (an IB school) so PB is going to start offering Mandarin in addition to Spanish and French. At least that’s what I heard.
But those school probably are too far west for you to commute to daily, Russ.