docs(api): retire the compound-name spelling from the live docs (#12176 stage 4) (#12381)

Stage 4 of the #12176 maintainer-ruled retirement of slash-bearing metadata
item names. Stage 1 (#12194) declared the item-name grammar and refuses every
slash-bearing name at the publish door; stage 3 (#12195) un-mounted the three
compound `:section` arities. These two pages were still teaching both.

content/docs/api/client-sdk.mdx:
  - The `meta.getItem` example addressed `'views/all_leads'` and promised
    compound names "pass through unencoded". Both halves are dead: the name
    is refused at the publish door, and #12195 put encodeURIComponent on
    every /meta item address, so there is no unencoded pass-through left.
    Respelled to the grammar's own published exemplar, `crm_lead.pipeline`
    under type `view` — which is exactly ViewItemNameSchema's `<object>.<viewKey>`
    identity, so the example teaches the enforced shape rather than a new one.

content/docs/api/error-catalog.mdx:
  - The unmintable-type entry documented TWO exemptions reaching the door.
    The compound-arity exemption is gone from the source (it was removed by
    #12194, not #12195 — `refuseUngrammaticalMetaItemName` runs before the
    probe and refuses every slash-bearing name), so the page has been
    describing a served behaviour that no longer exists. Reduced to the one
    surviving exemption, with a short retirement note so a caller who knew
    the old behaviour is not left guessing.
  - The residue that exemption documented — `PUT /meta/fieldz/a/b` being
    accepted — is closed with it, and the page now says so.
  - Two plural references to "the exemptions" corrected to the singular.

No changeset: docs-only, releases nothing (the `skip-changeset` case the
workflow prescribes). No ablation is owed — the change is prose and one
example, and the example is covered by check:skill-examples' semantic pass.


Claude-Session: https://claude.ai/code/session_01H9StxQgG2DPA26XzZZqnJB

Co-authored-by: Claude <noreply@anthropic.com>

Author: os-trump

content/docs/api/client-sdk.mdx

@@ -213,8 +213,8 @@ if (cached.notModified) {
 // Get auto-generated view
 const listView = await client.meta.getView('account', 'list');
 
-// Compound names (sub-resources) pass through unencoded
-const view = await client.meta.getItem('object', 'views/all_leads');
+// Sub-resource identity is DOT-qualified — `<object>.<viewKey>`, never a `/`
+const view = await client.meta.getItem('view', 'crm_lead.pipeline');
 
 // Per-item draft lifecycle (ADR-0033)
 await client.meta.publishItem('object', 'account', { message: 'go live' });

content/docs/api/error-catalog.mdx

@@ -573,7 +573,7 @@ the segment reaches for no declared type, so there is nothing to suggest.
 See the [Metadata API](/docs/api/metadata-api).  
 **Retry:** `no_retry` — replaying the same request against the same deployment returns the
 same `400`. ⚠️ That is stability, not determinism: the verdict is not a pure function of
-the type segment, and the exemptions below decide whether it fires at all.
+the type segment, and the exemption below decides whether it fires at all.
 
 `PUT /api/v1/meta/fieldz/showcase_task.title` answers `400` with:
 
@@ -589,21 +589,22 @@ the type segment, and the exemptions below decide whether it fires at all.
 ```
 
 <Callout type="warn">
-**Two shapes reach this door and are served, not refused** — neither of them visible in
-the message, so a caller who does not read this entry finds them by collision:
-
-1. **Compound arity.** A `name` containing `/` exempts the request, because at that arity
-   the `:type` segment carries an **object** name rather than a type claim:
-   `PUT /meta/lead/views/all_leads` is `type='lead'`, `name='views/all_leads'`, and no
-   static contract can enumerate the objects a deployment carries. Residue, stated rather
-   than hidden: `PUT /meta/fieldz/a/b` is therefore **accepted** — at that arity `fieldz`
-   is a claim about an object, not about a metadata type. The exemption is the **arity**,
-   not the name: `PUT /meta/lead/all_leads` is still refused.
-2. **Pre-existing namespace.** If `sys_metadata` already holds rows under that type key,
-   the write proceeds. The **store** decides this, never the caller — the probe runs only
-   after the static verdict has already fired, and it asks whether the *namespace* exists,
-   not whether your item does. This is what keeps rows minted before this refusal existed
-   editable by the tooling that copies and re-saves them.
+**One shape reaches this door and is served, not refused** — it is not visible in the
+message, so a caller who does not read this entry finds it by collision:
+
+- **Pre-existing namespace.** If `sys_metadata` already holds rows under that type key,
+  the write proceeds. The **store** decides this, never the caller — the probe runs only
+  after the static verdict has already fired, and it asks whether the *namespace* exists,
+  not whether your item does. This is what keeps rows minted before this refusal existed
+  editable by the tooling that copies and re-saves them.
+
+A second exemption used to sit beside it and is **retired**: a `name` containing `/` used
+to skip this verdict entirely, because at the compound `/meta/:type/:section/:name` arity
+the `:type` segment carried an **object** name rather than a type claim. Item names may no
+longer contain `/` — they are lowercase snake_case segments, optionally dot-qualified
+(`crm_lead`, `crm_lead.pipeline`), refused at the publish door otherwise — and the compound
+arities are un-mounted. The residue that exemption used to document is closed with it:
+`PUT /meta/fieldz/a/b` is no longer accepted, and no longer reaches this verdict at all.
 
 ⇒ **The same segment can be refused on one deployment and served on another, depending on
 stored state.** A `400` here is a statement about *this* deployment, not a portable
@@ -622,7 +623,7 @@ it.
 **Why it is refused rather than passed through.** A namespace nothing reads and nothing
 serves is not a harmless extra key — it accumulates silently, and every row in it is
 invisible to the tooling that lists, validates and ships metadata. Refusing at the mint
-door is what stops the first row from being written; the exemptions above are what keep
+door is what stops the first row from being written; the exemption above is what keeps
 that refusal from stranding the rows written before it existed.
 
 ⛔ **Not this error:** a segment that *misspells a type the platform declares* —