Stream trips as SSE (event: trip per trip, event: done at end). Trips that have booking links but no trip-visible bookings (only failed/voided/cancelled) are omitted; manually created planning trips with zero booking links remain unless bookedByMe or travelingOnly is true. bookedByMe and travelingOnly are self-scoped booleans for the authenticated caller; both true apply independently (a trip matches if it has a booked-by-me member booking and a traveled-by-me member booking, not necessarily the same one). Every trip is served entirely from stored data — dates, labels, prices, confirmation references, and vendorName on car bookings included; no live provider read happens on this request. holdExpiresAt is always null: hold metadata is not stored. Set MERCURY_TRIPS_SSE_ENABLED=false to fall back to a JSON array.