Ticket tracker switches board views with zero Firestore reads

An open-source ticket tracker called ticket-tracker loads each board's active tickets once and keeps them live, so switching saved views costs no database reads. Firestore cannot OR across fields and would need a composite index for every filter combination, which custom user-defined views would make impractical. Instead, filtering, sorting, grouping and swimlanes run as pure functions in the browser over the loaded tickets. Filters are nested and/or trees over built-in and custom fields, and tokens like 'me' or 'thisWeek' resolve against the viewer when the view is applied. The approach is designed for boards of roughly 5,000 active tickets, or about 5 MB.