011: postgres worked through, and "one kind of edge" was wrong

The tidy version said a module provides names and requires names and that is the
only edge. Working postgres through completely disproves it.

A small game wanting to store data does not require postgres to EXIST. It
requires postgres to MAKE IT A DATABASE and hand back credentials. Those are
different relations in every way that matters: one creates something per
consumer, carries a payload back, can be revoked, and leaves the provider
holding state about who was granted what. The other creates nothing.

So: two kinds of edge, one graph. Instantiation implies presence; presence does
not imply instantiation. The current system already had exactly this split —
`dependencies` for presence, `requires: provision:` for instantiation, with the
resolver deriving one from the other. analysis.md called that derivation a
convenience. It is not: it is the correct relationship between two genuinely
different relations, and the design had collapsed them.

Postgres also turns out to be nine things, not one. A container. Persistent
state where moving nodes is a migration rather than a reschedule. Configuration
partly derived from the machine's hardware. A tool surface. A provisioner. Its
own bookkeeping about what it granted, which is not the data it stores. An
exposure decision per node it runs on. Credentials it generates, which means a
provisioning edge carries a secret. And health that is not "the container is up".

Four questions the worked example makes concrete rather than abstract. WHICH
postgres, when there are two — a consumer of `terminal` does not care and a
consumer of a database cares permanently. How many instances a module should
have, which cannot be a global rule because one-per-mesh is wrong for a store a
disconnected node needs and one-per-node is wrong for the mesh's own registry.
What happens to a grant when its consumer is removed, where dropping is data
loss and keeping is a leak. And whether a declaration is composed PER NODE from
what that node reported — because tuning follows hardware the control plane
cannot know, and the alternative is the host deciding, which ADR 0037 forbids.

01-RESEARCH/011-the-module-graph/00-overview.md

@@ -17,6 +17,13 @@ touches:
 Whether the catalogue's missing structure is a **graph** — modules declaring what they need,
 what they offer, and what they exclude — and what that replaces.
 
+**[`worked-postgres.md`](worked-postgres.md) works one module through completely**, and breaks
+the tidy version. A database is nine things, not one — and a small game asking the mesh for its
+own database shows there are **two kinds of edge**: *presence*, where the thing must exist, and
+*instantiation*, where a provider makes something for a consumer and hands back credentials.
+Instantiation implies presence and not the reverse. The current system already had this split
+and the design had collapsed it.
+
 **[`features.md`](features.md) answers what happens to `feature`.** It is one word for four
 things spanning three tiers — artifacts built once per version, resources applied to a machine,
 actions run against something that is not this machine, and checks that are requirements in