docs(cli): document the objectui check expression refusal, with its changeset (objectui#4795)

The `objectui check` page said only unreadable JSON fails the run; a refused
`${…}` on a text key its node never evaluates now does too. The page names
the rule, the two sub-rules and the real output, and the changeset declares
the new refusal as a minor for `@object-ui/cli`.

Claude-Session: https://claude.ai/code/session_012UwY3ahMixEFkfTUxMVkYm
Co-authored-by: Claude <noreply@anthropic.com>

Author: claude

.changeset/4795-check-bindable-text-keys.md

@@ -0,0 +1,32 @@
+---
+'@object-ui/cli': minor
+---
+
+feat(cli): `objectui check` refuses a `${…}` on a text key its node never evaluates
+
+`SchemaRenderer` evaluates an expression on the closed text keys `title`,
+`label`, `value` and `description` only where `@objectstack/spec`'s
+`expressionBindableTextKeysFor(type)` lists that key for the node's type.
+Anywhere else the expression is never resolved, so the user sees
+`${data.total}` as literal text, or nothing at all — and no step before the
+browser said so.
+
+`objectui check` now refuses such an expression in every file it recognises as
+an ObjectUI schema, and the run exits non-zero. The refusal names the key, the
+path to it (spelled as `objectui validate` spells paths), the keys that type
+does evaluate, and the channels `SchemaRenderer` evaluates. Types with no row in
+the carriage map are refused too: `text.value` and `action:button.label` are
+never evaluated.
+
+- **Component nodes only**: the file's root node and every node its `children`
+  hold. Objects under other keys, such as a form's `fields` entries, are
+  definitions rather than nodes and are not judged. A root of type `page` keeps
+  its own `title`, which is a page key; its `children` are still judged.
+- **The type is matched as written**, as the runtime matches it: `ui:card` has
+  no row, and is not read as `card`.
+- **A type no registered component answers to** gets a warning instead of a
+  refusal, because a custom renderer may evaluate its own keys.
+
+The key vocabulary and the per-type carriage map are read from
+`@objectstack/spec`, now a declared dependency of `@object-ui/cli`, so a row
+added upstream moves this check and the runtime together.

content/docs/utilities/cli.mdx

@@ -224,13 +224,37 @@ distinction matters:
      Issue at map: Unrecognized key: "latitudeFieId"
 ```
 
-A run with no parse errors ends on a tally rather than a pass: how many
-recognised files validated, how many were recognised by a structural key and not
-validated, and how many did not validate, followed by a pointer to
-`objectui validate` for the verdict.
+#### Expressions on text keys that are never evaluated
+
+`SchemaRenderer` evaluates a `${…}` expression on the closed text keys `title`,
+`label`, `value` and `description` only where `@objectstack/spec`'s
+`expressionBindableTextKeysFor(type)` lists that key for the node's type. On any
+other type, the expression is never resolved: the user sees its literal text, or
+nothing. `objectui check` refuses it in every recognised file:
+
+- **Component nodes only.** The file's root node and every node its `children`
+  hold, at any depth. Objects under other keys (a form's `fields`, a grid's
+  `columns`) are definitions, not nodes, and are not judged. A root whose `type`
+  is `page` keeps its own `title`: that is a page key, while its `children` are
+  still judged.
+- **The type is matched as written.** `ui:card` is not `card`, exactly as at
+  render time.
+- **A type no registered component answers to** is warned about, not refused: a
+  custom renderer may evaluate its own keys.
 
-Only unreadable JSON makes `objectui check` exit non-zero; everything above is a
-report. Use `objectui validate` when you want a failing exit code.
+```text
+x Unevaluated expression in dashboard.json at children → 0 → title: "statistic" never evaluates `title` (it evaluates only `label`, `value`, `description`), so the expression is never resolved: the user sees its literal text, or nothing.
+   Channels SchemaRenderer evaluates: `label`, `value`, `description`, `content`, `properties.title` (evaluated, then hoisted onto the node); or resolve the value in the host before the schema reaches SchemaRenderer.
+```
+
+A run with no parse errors and no refused expression ends on a tally rather than
+a pass: how many recognised files validated, how many were recognised by a
+structural key and not validated, and how many did not validate, followed by a
+pointer to `objectui validate` for the verdict.
+
+Unreadable JSON and a refused expression make `objectui check` exit non-zero;
+everything else above is a report. Use `objectui validate` when you want a
+failing exit code on a document that does not validate.
 
 ### `objectui doctor`