Phase 1: content source of truth — 40 documents across six areas

Satisfies the Phase 1 Definition of Done:

- content/ validates cleanly against the frozen schema. `make validate`
  reports OK: 40 document(s) validated, 0 violations.
- Six areas exist, each with an L1 entry: ai-overview, platform-overview,
  edge-overview, products-overview, history-overview, about-overview.
- All six areas have an L2 entry: ai-systems, platform-estate, edge-fleet,
  products-business, history-engagements, about-narrative.
- 28 L3 artefact stubs under content/<area>/l3/. Every artefacts[].url in
  every document resolves to one of them; the validator proves there are no
  dangling references (and a deliberately broken copy exits 1).
- Every metric value traces to a source line in the evidence notes or the
  approved metric set in reference/content-map.md (per-metric citations are
  recorded in the AUD-131 completion comment).
- Every document carries confidence and last_verified=2026-10-26; the
  validator rejects a missing or non-canonical value.
- docs/content-redaction.md records the redaction pass: identifiers, third
  party personal data, credentials and infrastructure detail excluded, with
  reasons, plus the two numbers that are reported rather than smoothed.

Honesty positions held: 3 businesses active (12 adoptions over time),
Where-Woof deployed and pre-market, failures kept in (edge-failures), no
promotion of in-progress work to delivered.

No site code, no templates, no CSS, no rendering (Phase 2).

content/platform/l3/platform-backups.md

@@ -0,0 +1,35 @@
+---
+id: platform-backups
+area: platform
+level: 3
+title: "Artefact — Backups and restore runbook"
+claim: "Three tiers — local snapshots · a copy on another machine · an offsite copy — with retention stated in the job and a restore runbook kept beside them."
+confidence: running
+period: "2020–"
+tech: [Borg, Kopia, Backrest, AWS S3, systemd, NFS]
+metrics: [{label: "backup tiers", value: 3}, {label: "retention windows in the primary job", value: 3}]
+artefacts: []
+public: true
+last_verified: 2026-10-26
+tags: [platform, backups, restore, artefact]
+---
+
+# Artefact — Backups and restore runbook
+
+**Status: stub.** Redacted job definitions and the restore runbook land in Phase 7. Passphrase locations and remote paths are removed before publication.
+
+## What the artefact is
+
+The backup design: Borg jobs on the two desktop hosts to local storage with a network copy, Kopia and Backrest on the edge host to network storage, an offsite copy in object storage, and retention expressed in the job (seven daily, four weekly, three monthly, plus annual on the edge). Beside it, the restore runbook and the list of what is deliberately not covered.
+
+## What it proves
+
+That failure was designed for: three tiers cover disk loss, machine loss and site loss, and the restore path is written down rather than recovered from memory at the worst possible moment.
+
+## Limits stated on the page
+
+Not everything is covered, and the page says so — one storage host is itself a single point of failure for some repositories, and the file server has no backup of its own. Those are known gaps with owners, not oversights to be hidden.
+
+## When it is delivered
+
+Phase 7. Source: the infrastructure reference and the backup system notes, read 2026-10-26.