963f307cfc
Generic directed links between plant/fungus/insect entities (subject_kind/slug,
predicate, object_kind/slug). Predicates: pollinates, feeds_on, preys_on,
parasitizes, attracts, mycorrhizal_with, grows_on. Interaction model,
db/interactions.rs (flexible filtered query + per-entity lookup, upsert),
/api/v1/interactions + /{kind}/{ref}/interactions routes. Wired into
stats/export/llms. seed_interactions.py: derives preys_on links + curated
pollinator/mycorrhizal/pest links (existence-checked).