Multiple selected actors now combine as OR (any) by default — click several cast
and see films featuring ANY of them — instead of the old hardcoded AND that
emptied the grid. An AND (all) toggle in the ACTIVE filter section (shown for 2+
actors, mirroring the genre match toggle) narrows to films with ALL of them.
Backend actor_mode param mirrors genre_mode. Verified: OR John Goodman|Douglas
M. Griffin = 11 films; AND = 1 (10 Cloverfield Lane). (Plex cast-explore S2)