segments
Intersect L0 — segment core (intersect/segments).
The pure, primitive engine. It reasons over patterns already split into
path segments (SegmentPattern); it never parses strings and never touches
the filesystem. Pairwise and minimal — the reusable, portable, zero-dep
heart of the library. See
docs/planning/decisions/D-4FRD-intersect-api/layered-api.md.
The type surface is the contract the fixture corpus specifies. The engine is
a synchronized product of two per-pattern sequence automata plus reachability
(./automaton.ts, ./product.ts); it has zero runtime dependencies.