Issue 146: a first node now enrols, and is enrolled twice

Two more faults behind the three already fixed. The account a token is the
password of was never recorded, and the comment above the issuing code said
it was; issuing now records it. Placing the composed list at genesis is the
other half — the control plane says what it composed and whoever raises the
machine writes it beside the bus, because no declaration can reach a machine
that has not enrolled.

With that a first node enrols. It is then enrolled twice from one attempt,
each minting a credential, and it keeps the answer to the first while the mesh
keeps the second. The trail for that one stops at a duplicate that survived
message-id deduplication.

04-ISSUES/146-the-foundation-cannot-be-raised-on-the-bus-the-mesh-runs-on/01-diagnosis.md

@@ -82,6 +82,54 @@ managing, or genesis carries a user list that includes the first node's enrolmen
 takes over from there. Both are decisions, not patches, and both belong to the genesis step that was
 deliberately left until last.
 
+## 5 — the composed user list has to be placed by hand at genesis *(fixed)*
+
+The account a token is the password of is **not recorded at all**: the composer names an enrolment
+user for every machine with a live token, nothing minted a credential for it, and the composition
+left it out as a user with no password. The comment above the issuing code already claimed
+otherwise — *"the account is created before the token is handed over"* — which is how it went
+unnoticed. Issuing a token now records that account, with the token's own secret as its password,
+because that is the string the machine will present.
+
+Placing it is the other half. The list reaches the machine running the bus in that machine's
+declaration, which a machine that has not enrolled does not get, so at genesis it cannot arrive
+that way. **The control plane composes and says what it composed** — `broker accounts`, to standard
+output — and whoever is raising the machine writes it beside the bus's configuration and makes the
+server re-read it. Twice, because two accounts come into existence at different moments: the
+enrolment when the token is issued, and the machine's own when it enrols. A control plane that
+wrote the file itself would have to know where the bus keeps its configuration and how to make it
+reload, which is the module's knowledge and is what the module takes over on the first push.
+
+With that, **a first node enrols against the bus it just raised** — measured, from bare, in the
+lab.
+
+## 6 — and is enrolled twice, keeping a credential the mesh has replaced *(open)*
+
+```
+mesh-controller: enrolled anchor
+mesh-controller: enrolled anchor      (the same second)
+```
+
+One `enrol` on the machine, two enrolments in the control plane. Each mints the node a fresh bus
+password and returns it; the machine keeps the answer to the first, and the mesh keeps the hash of
+the second. The machine then reconnects for ever as a user whose password the mesh rotated out from
+under it — *authentication error - User "node.anchor"* on the bus, `Authorization Violation` in the
+host's log, and a node that never reports.
+
+What is ruled out: the host asking twice — it asks again only when the mesh says *try again*, and
+a refused attempt is not logged as an enrolment. Redelivery by the consumer — there is one
+consumer, its acknowledgement window is thirty seconds, and the handler is quick.
+
+What is left: the client re-publishing when an acknowledgement is slow, which is what its defaults
+do. That was addressed by giving the publish a message id derived from its own bytes, so the stream
+discards the copy — **and the duplicate survived it**, so either the id is not reaching the stream
+or the second copy is not a copy. This is where the trail stops.
+
+Worth saying plainly: **the mint is the fragile part, not the delivery.** An enrolment answered
+twice is survivable if the answer is the same both times, and it cannot be — the mesh keeps only
+the hash, so a second answer is necessarily a different credential. Whatever closes this either
+makes the enrolment arrive once, or stops the second arrival from rotating anything.
+
 ## Where it belongs
 
 `mesh-host` (the bundle and the enrolment path) and `mesh-controller` (the certificate command, and