What kind of fluid is it—manī or madhī—if it's one or two barely visible drops, discharged unintentionally after a lust-inducing thought? And is the gush of manī a condition for performing ghusl (ritual bath) from janābah (state of ritual impurity) in this case?

Both mani (sperm/seminal fluid) and madhy (pre-seminal fluid) have distinguishing characteristics. The man's mani is a white, viscous, thick fluid that usually exits in gushes, accompanied by pleasure, and is followed by a feeling of exhaustion. Its scent resembles that of a date palm spathe or dough. It necessitates ghusl (definition) (ritual bath). As for madhy, it is a viscous fluid, thinner than mani, that exits after arousal from thought or looking, and it is intermittent. It does not necessitate ghusl; rather, it only requires washing the penis and invalidates ablution (wudu').