Custom Sources

Bring your own source with an Observer and an analyzer pass.

A new source needs two things:

1. an Observer that turns the source into content-addressable artifacts (runs in ekos build);
2. a recovery pass that turns those artifacts into KIR objects, relationships and evidence (runs in ekos recover).

Both plug in through the extension seam without forking EKOS. Any new ObjectKind::Custom you emit must be registered in ekos_kir::custom_kinds::REGISTRY with the right structurally_keyed flag — a CI test enforces it.