ADR-0005 still names `metadata-customization.zod.ts` as a kept, future-phase model after #13135 retires it

[os-trump]

Blocked-by: #13135

Filed from the #13135 retirement PR as an out-of-scope finding. ⛔ Not fixed there: docs/adr/** is a governed surface, and that card's charter explicitly routes ADR corrections to their own draft-only, human-merged PRs (the sibling case is ADR-0126 §6.4, owned by #13136).

What goes stale

#13135 deletes packages/spec/src/kernel/metadata-customization.zod.ts whole. Two lines in docs/adr/0005-metadata-customization-overlay.md still describe that module as present and deliberately retained:

• line 123 — "A finer-grained patch model (RFC 7396, 3-way merge) is out of scope — MetadataOverlaySchema in metadata-customization.zod.ts already specifies it; we keep that model available for future phases but do not implement merge yet."
• line 221 — lists packages/spec/src/kernel/metadata-customization.zod.ts under the ADR's file inventory as "pre-existing MetadataOverlaySchema (kept; field-level patches are a future phase, not implemented here)".

Once #13135 lands, both sentences name a module that no longer exists, and the second promises a future phase that ADR-0126 §6 wall 3 has since ruled out (upgrades rewrite the packaged base; customer choices live in the ledger and are never merged).

Why this is not a re-litigation of ADR-0005

ADR-0005's own decision — the org-scoped overlay (allowOrgOverride on DEFAULT_METADATA_TYPE_REGISTRY, sys_metadata org rows, the layered code/overlay/effective read) — is untouched by #13135 and keeps working exactly as before. What needs correcting is only the two sentences pointing at the paper module as a retained future direction. Per Prime Directive #13 the reversal is already carried by a superseding ADR (ADR-0126 §6 wall 4, "nothing may build against it") plus the maintainer ruling of 2026-08-29 on #12057 (「同意」), so this card is a factual text correction, not a new decision.

Suggested shape

Amend the two lines to record that the paper model was retired under ADR-0049 enforce-or-remove, pointing at ADR-0126 for the model that replaced the never-built merge story. Reasonable to fold into #13136's ADR pass if the reviewer prefers one governed-surface PR over two.

Verification of the finding

$ git grep -n "metadata-customization.zod\|MetadataOverlaySchema" -- docs/adr/0005-metadata-customization-overlay.md
docs/adr/0005-metadata-customization-overlay.md:123: ... `MetadataOverlaySchema` in `metadata-customization.zod.ts` already specifies it ...
docs/adr/0005-metadata-customization-overlay.md:221: ... pre-existing `MetadataOverlaySchema` (kept; ...)

Deliberately filed unassigned for PM triage.