Order the records the way the system is learned

Jochen asked whether the order made sense. It did not -- it followed when
things happened to be decided, which after consolidation is fictional anyway
since record 5 alone folds decisions taken across a week.

Concretely wrong before: the domain statement sat at 8, after five engineering
rules; the constitution was scattered across 5, 12 and 17; the tiers landed at
15, 16, 21 and 22 with process records in between.

Now it walks: what the mesh is (1-3), its tiers from the bottom up (4-8), what
runs on them and how it gets there (9-10), how it is built (11-16), how it is
checked (17-18), how we work (19-23).

Two things made this safe rather than free. It is a permutation, not a
compaction, so the renames go through temporary names -- otherwise two files
want one slot and one is lost. And the reference rewrite is a single
simultaneous pass, because almost every number moved into a slot another number
was vacating; replacing one at a time would have cascaded and pointed things at
the wrong record while still resolving.

Verified: 284 [ADR NNNN](path) links across the repository, all with matching
text and target.

The ordering principle is now stated in 19 rather than left implicit -- the
repository already said "the numbering is the flow" about its folders, and
there was no reason for the records to be the exception.

02-DECISIONS/0021-hq-is-the-source-of-the-constitution.md

@@ -0,0 +1,67 @@
+---
+status: accepted
+date: 2026-08-23
+deciders: jochen
+reconstructed: false
+---
+
+# 21. HQ is the source of the mesh constitution
+
+## Context
+
+[ADR 0020](0020-the-mesh-is-governed-by-a-constitution.md) established a canonical rule set,
+injected into every eligible design session and checked before output is accepted. It lives in
+the knowledge base, where the orchestrator reads it.
+
+HQ separately carried a document stating overlapping rules with the reasoning that earned each
+one. Two texts, one enforced and one not.
+
+That arrangement has a predictable outcome and it is not a tie. The enforced copy wins by
+default, because it is the one that blocks work. The reasoned copy quietly stops being true,
+and the rules survive without the incidents that justify them — at which point a rule reads as
+arbitrary, and an arbitrary rule is the kind people route around.
+
+## Considered options
+
+1. **The knowledge-base page is the source; HQ points at it.** Rejected, though it is the
+   honest description of what was already happening. It leaves the reasoning downstream of the
+   rule, and the reasoning is the part that makes a rule survive a challenge.
+2. **Accept the overlap and let both stand.** Rejected: two authorities is no authority, and
+   the drift is silent.
+3. **HQ is the source; the governed page is derived and published from it.** Chosen.
+
+## Decision
+
+[`00-META/how-we-build.md`](../00-META/how-we-build.md) is the source. The governed page the
+mesh injects is **derived** from it — the rules without the reasoning — and is never edited
+directly.
+
+Publishing is a playbook step, not a manual act, and it ends with **reading the page back and
+verifying the change is present**. A publish that reported success and did nothing is exactly
+the failure class this mesh keeps producing
+([ADR 0010](0010-delivery.md)).
+
+Section numbering is stable, because the orchestrator and the review fragments cite sections by
+number.
+
+## Consequences
+
+- One source, many surfaces — the same argument HQ's separation already rests on
+  ([ADR 0019](0019-how-this-repository-works.md)), applied to the rules themselves.
+- Each rule keeps the incident that earned it, in a place that is reviewed as a diff.
+- An edit to the derived page survives until the next sync and then vanishes. The playbook says
+  so, and nothing mechanically prevents it.
+- **The sync is manual and is the weak point.** An unsynced rule is a rule the mesh does not
+  enforce, whatever the source says — so the playbook requires the failure to be stated rather
+  than passed over. This is the same class of gap as
+  [`04-ISSUES/006`](../04-ISSUES/006-hq-is-not-indexed-into-the-knowledge-base/00-report.md),
+  and it is worth watching for the same reason.
+- The document grew from four rules to seven sections, because it now has to carry everything
+  the mesh enforces rather than only what someone thought to write down.
+
+## References
+
+- [`00-META/process/05-constitution-sync.md`](../00-META/process/05-constitution-sync.md) —
+  the sync, including the read-back.
+- [ADR 0020](0020-the-mesh-is-governed-by-a-constitution.md) — the governed page and why it
+  exists.