Environment variables

Variable	Value	What it is for
RLX_PRESET_DIR	a directory	Read presets from here instead of the seeded per-user directory; edits to *.toml there hot-reload live
RLX_TIER	floor | rich	The same pin as --tier, for a one-off run
RLX_GRID_SCALE	0.25–1 | auto	The same override as --grid-scale, for a one-off windowed run. A bad value is reported and ignored

RLX_PRESET_DIR is read by the headless shot CLI as well as by the app, so a capture and a live run resolve the same library.