-- Where each module came from, and whether what the mesh holds is still current.
--
-- novox/hq ADR 0010: delivery is a comparison, not a pipeline. The control plane holds what
-- source exists and what has been built from it, and builds the difference. So both halves have
-- to be written down, and *is this current?* is a question about two columns rather than
-- something you find out by building.

alter table module add column source      text;  -- where it comes from
alter table module add column ref         text;  -- the branch followed there
alter table module add column built_from  text;  -- the commit this manifest was read at
alter table module add column source_head text;  -- the newest commit the source is known to have

-- When the mesh last learned the source had moved. Kept apart from `registered`, which is when
-- the manifest last changed: a source that moved and was never built is exactly the state this
-- exists to make visible, and one timestamp could not show it.
alter table module add column source_seen timestamptz;

-- A module with no source is not a fault. It was handed over directly -- which is how every
-- module got here before this existed, and how a one-off still arrives. It is simply never out
-- of date, because there is nothing it could be behind.