Bounds cacheDirectory/originals to an adaptive limit: min(configured max,
bytesUsed + bytesFree - reserve), bytesFree from statfs, so it tracks disk
pressure (status().originalsLimitBytes exposes it). Each original write evicts
least-recently-used originals until usage fits; last-use is the file mtime,
bumped on every read that returns a path, so order survives restarts.
Never evicted: pinned originals and every original whose write overlaps the
evicting one — its own and any concurrent sibling's, since content writes run in
parallel. So an over-budget fetch keeps the path it returns, and no write can
delete a sibling's file before that fetch returns it; such files become eligible
on a later, non-overlapping write. Defaults: 100 GiB limit, 50 GiB reserve.
Model: opus-4-8
sneak