docs(spec): drop the stale "the id wins" sentence and add the changeset

The visitor's lead comment still described the id route as beating the
page-name route for a header that carries an id -- the sentence the gate
below it now contradicts. Rewritten to say what the code does.

Changeset: `minor` on `@objectstack/spec`, stating the behaviour change and
the FROM -> TO mapping for a bundle that used the components key.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01T6HeZvT9wdSJD1ZxJb5Eno

Author: claude

.changeset/page-header-page-name-route-canonical.md

@@ -0,0 +1,40 @@
+---
+"@objectstack/spec": minor
+---
+
+`translatePage` now reads a region-level `page:header` by **page name only**. The id route
+(`pages.<page>.components.<headerId>.*`) is no longer read for that component, even when it carries an `id`.
+
+**Behaviour change, stated plainly:** a bundle that overrode a region-level header's title through
+`pages.<page>.components.<headerId>.title` now falls back to `pages.<page>.title` (which itself falls back to
+`pages.<page>.label`). The components key still parses — nothing is removed from `TranslationBundleSchema` — it is
+simply no longer the address for this one component.
+
+```
+FROM  pages.<page>.components.<headerId>.title   # region-level page:header — no longer read
+TO    pages.<page>.title                         # …and .subtitle for the subtitle
+```
+
+Fix in one line: move the string from the components entry up to the page's own `title` key, and delete the
+components entry for that header id. `os i18n extract` has always offered exactly the `TO` key, so a bundle
+generated or checked by the CLI already writes it.
+
+**Blast radius, as measured on the card (inherited, not re-measured here):** HotCRM found **zero** such overrides —
+all five of its region-level headers carry ids and none writes the components key.
+
+**Why.** Both sides were deliberate and they disagreed. The extractor skips a region-level `page:header` on purpose
+(its copy is offered under `pages.<page>.title` / `.subtitle`, and emitting it twice would put one string under two
+keys); the resolver read the id route on purpose (the more specific route wins). Together they produced the exact
+failure `walkAddressedPageComponents` was extracted to prevent — the resolver reading an id the extractor omits — so
+the key an author reached for won silently while the key the tooling reported as translated lost. The maintainer
+ruled (2026-09-06, decision batch #58, verbatim 「同意」) that the page-name route is canonical: one component, one
+address. `title` and `subtitle` now follow the same rule, closing the asymmetry where `title` had two addresses and
+`subtitle` — never in `PAGE_COMPONENT_COPY_KEYS` — had one.
+
+Unchanged: a `page:header` **nested** inside a container is reached by the id route only, as it always has been; and
+a region-level header's id still claims its bundle entry and still blocks a nested namesake, which is what the
+extractor does too.
+
+Not `major`: nothing an author can write is removed or renamed. `pages.<page>.components.<id>` remains a declared,
+parsing, resolving address for every other component — including a nested `page:header` — so there is no key to
+tombstone and no ADR-0087 conversion to register. Recorded here so the choice is checkable rather than assumed.

packages/spec/src/system/i18n-resolver.ts

@@ -1745,14 +1745,13 @@ export function translatePage<T extends PageLike>(
   // `children` after the visitor returns, so the overlay never contends with
   // the descent for a key (`children` is not a copy key).
   const regions = walkAddressedPageComponents(doc, (component, { nested, id, addressed }) => {
-    // Per-component copy (#6080) — addressed by the component's own id, so it
-    // is strictly more specific than the page-name route below and is applied
-    // first. A `page:header` that DOES carry an id can therefore be translated
-    // either way, and the id wins. `addressed` carries the ruled collision
-    // arbitration (#12961), so a looked-up entry is this component's alone;
-    // within one call `lookupPageComponentCopy` is a pure function of the id
-    // (bundle, page name and options are fixed), so the walk's claim-on-first-
-    // sighting selects the same component a claim-on-resolved-lookup would.
+    // Per-component copy (#6080) — addressed by the component's own id, and
+    // applied before the page-name route below. `addressed` carries the ruled
+    // collision arbitration (#12961), so a looked-up entry is this component's
+    // alone; within one call `lookupPageComponentCopy` is a pure function of
+    // the id (bundle, page name and options are fixed), so the walk's
+    // claim-on-first-sighting selects the same component a
+    // claim-on-resolved-lookup would.
     //
     // The one component this route does NOT serve is a REGION-LEVEL
     // `page:header`: its copy is addressed by page name below, and reading