Approve 0054-0056, apply them, and fix the two smaller findings

0003 is now superseded by 0056. Nothing is left proposed.

Applied:
- 06 corrected from ten contexts to seven plus the api, each row now stating
  why it passes the more-than-one-node test. work, knowledge and stream are
  named as mesh-hosted rather than dropped; `ai` folds into config; `record`
  is deferred explicitly rather than listed. Its frontmatter now cites 0055.
- how-we-build §4 amended per 0054, and the derived page republished by
  playbook 05.

The sync found the drift the playbook exists to catch: the published §4 and
the source did not say the same thing. The source said "four accidents, not
four boundaries"; the published page said "one intent expressed four times",
and only the published page carried the scope caveat. Same rule, two texts,
already diverging. Verified the republish by reading back -- the new rule is
present and the old section's body returns nothing -- rather than trusting the
success message.

The two smaller findings:
- 0051 separated the transport identity from the declaring authority. It said
  the token carries "an address" and "the identity to expect" without saying
  what the node dials. It dials the broker, so pinning only that would make the
  control plane's authority transitive and let a compromised broker forge
  declarations -- which, since the host applies whatever the link delivers, is
  the whole machine. The token now carries four things, and declarations are
  signed and verified per declaration. Cost recorded: rotating the signing
  identity is fleet-wide.
- 0026 no longer restates 0022's rule about generated views. 0022's own words
  are "prose does not restate status; one place, and two is one too many",
  which is what 0026 was doing to it.

00-META/how-we-build.md

@@ -114,12 +114,14 @@ and it runs on no node at all.
 
 Anatomy makes attractive names and poor boundaries. Name the thing the domain calls it.
 
-### Group by domain, not by single function
+### Things that change together share an authority, not a package
 
-A module is a purpose, not a piece of software. Four modules that together constitute "how a
-node is reachable" and cannot be assigned, versioned or replaced as one thing are four
-accidents, not four boundaries.
-[ADR 0017](../02-DECISIONS/0017-modules-outside-the-core-are-grouped-by-domain.md)
+When several modules always change together under one intent, name the **context** that decides
+for them. Do not merge them into one module: they are delivered to different nodes, and a module
+that must be assigned where half of it is unwanted is not a boundary either.
+
+Coherence is a context. Delivery is a module. Relationships are edges, not folders.
+[ADR 0054](../02-DECISIONS/0054-things-that-change-together-share-an-authority.md)
 
 ### Contexts integrate through the record, never through a shared schema