Consolidate: 65 decision records to 52

Jochen: a normal application has 3-5 ADRs, maybe 10 for a large one, and we are
at 65. Fair, and the cause is mine -- I recorded every FINDING as a decision
rather than every fork in the road.

Two merges, both cases where one decision had been split across many records
because it was taken over several days rather than at once.

0019 absorbs ten records about how this repository works: what it is and that
it is public, the folder flow, the two design layers, the issue front door,
status in frontmatter, playbooks, the naming rule, the product name. Those were
never ten decisions -- they were one, seen from ten angles as the repository
took shape.

0016 absorbs the five about the lab: a node is a virtual machine, a router is
scenery, a scenario declares the underlay, a scenario is a closed address
space, and the two scenario classes. Same pattern -- one design, split by the
order it was worked out in.

The consolidated 0019 also raises the bar for what earns a record, since that
is what produced 65: a record is warranted when there is a genuine fork -- a
direction reversed, an alternative that will be proposed again, something
contested. A finding is not a decision, and a bug is certainly not. Everything
else belongs in the design document where the reasoning is actually read.

The checker earned its place here. Deleting nine records left 13 dangling links
across the repository and it named every one, including in AGENTS.md. Nothing
was found by reading.

Remaining clusters worth the same treatment: the host (8 records), delivery
(5), modules (6), connectivity (4), substrate and control plane (4). That would
be 52 down to roughly 30.

03-DESIGN/01-to-be/01-end-to-end-testing.md

@@ -4,9 +4,9 @@ status: in-progress
 code: [mesh-lab]
 updated: 2026-08-23
 decisions:
-  - 02-DECISIONS/0016-a-lab-node-is-a-virtual-machine.md
-  - 02-DECISIONS/0029-the-labs-first-scenario-has-no-pipeline.md
-  - 02-DECISIONS/0030-the-repository-structure.md
+  - 02-DECISIONS/0016-the-lab.md
+  - 02-DECISIONS/0016-the-lab.md
+  - 02-DECISIONS/0019-how-this-repository-works.md
 ---
 
 # End-to-end testing
@@ -37,7 +37,7 @@ today, that is a gap in the vocabulary rather than a reason to privilege that sh
 
 The design below describes a scenario as a complete mesh — forge (Gitea), coordinator,
 delivery cascade — because what it tests is a module. **That is the larger of two classes, and
-not the first one built** ([ADR 0029](../../02-DECISIONS/0029-the-labs-first-scenario-has-no-pipeline.md)).
+not the first one built** ([ADR 0016](../../02-DECISIONS/0016-the-lab.md)).
 
 | | **Bootstrap scenario** | **Full scenario** |
 |---|---|---|
@@ -127,7 +127,7 @@ drifts.
   a mesh named by the request instead.
 - **Scenarios must be concurrent and cheap.** Several agents working means several scenarios
   at once, each needing its own network and nodes. A lab node is a virtual machine
-  ([ADR 0016](../../02-DECISIONS/0016-a-lab-node-is-a-virtual-machine.md)), and snapshots are
+  ([ADR 0016](../../02-DECISIONS/0016-the-lab.md)), and snapshots are
   what make repetition cheap — restoring a scenario costs far less than building one. The
   earlier argument here, that only system containers made this affordable, was superseded: the
   scale it assumed was invented rather than required.