docs(changeset): say only what holds for every chart type about the now-refused axis shapes (objectui#10518)

Review round 2 showed that the round-3 conditions were too broad. Whether
a no-category or no-field shape draws depends on the chart type and on the
rows: a `name` column, or the `value` fallback. The lead-in now says that
several of the now-refused documents draw a chart today, and that what the
rest draw depends on the chart type, the rows and the node's other
sources. The bullets state only equivalences the renderer guarantees: a
dropped key changes nothing; a bare string reads as `{ field }`; a list,
a non-object or a missing field names no category; a no-field entry adds
no series. Prose only; the frontmatter is byte-identical.

Co-Authored-By: Claude <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014mXUNuFomfj24w7s1pZzhN

Author: claude

.changeset/10518-object-chart-y-axis-declared.md

@@ -21,32 +21,28 @@ the `object-chart` sibling of the objectui#7690 declaration on `ChartSchema`.
   has no string arm (seat decision on objectui#10518, option A).
 
 ⚠️ Shipped as `minor`, not `patch`: documents that validated before now **refuse** (the accept set
-narrows), and most of them draw a chart today. The exceptions are named in their bullets:
+narrows). Several of them draw a chart today, which is why this ships as `minor`; what the rest draw
+depends on the chart type, on the rows, and on the node's other category and series sources:
 
 - An `xAxis` object with a malformed value (`min: 'zero'`, `position: 'middle'`), an undeclared
   key (`grid`, `logScale`) or no `field`. It is refused as one issue at `xAxis` whose message carries
-  the spec's own diagnostic, including its alias hint. With a malformed value or an undeclared key
-  the chart draws today, because the object's `field` still names the category column. An object
-  with no `field` names no category, so the chart draws only when another source names one: an
-  `xAxisKey`, or the dimension of a dataset-bound chart. Otherwise it draws a refusal instead: the
-  objectui#8168 missing-category-axis screen on an object-bound chart that also declares no
-  `aggregate.groupBy`, and the renderer's `missing-category-key` error on any other chart.
+  the spec's own diagnostic, including its alias hint. The renderer drops a malformed `min` or
+  `position` and never reads `grid` or `logScale`, so an object carrying them draws exactly what it
+  draws without them. An object with no `field` names no category of its own.
 - An `xAxis` written as a bare column name (`xAxis: 'status'`), a list of axis objects, or any other
   non-object value. It is refused with the remedy `xAxis: { field }`. The renderer's normalizer still
   honours a bare string as a tolerance, and that is unchanged, but no producer on this node writes
-  one. A bare string draws a chart today. A list or another non-object names no category either,
-  so it draws a chart only under the same condition as an `xAxis` object with no `field`, and
-  otherwise the same refusal.
+  one. A bare string names the category column exactly as `{ field }` does, so it draws what that
+  object draws. A list or any other non-object names no category, like an object with no `field`.
 - A `yAxis` entry with a malformed value (`stepSize: 'big'`, `position: 'middle'`), an undeclared
   key (`logScale`, `grid`) or no `field`. It is refused at the entry's own path. The renderer ignores
-  what it cannot read and draws the rest. The exception is a chart whose series come from `yAxis`
-  alone (no `series`, no `categories`, not dataset-bound): there an entry with no `field` plots
-  nothing, and when no entry names a `field` the chart draws the renderer's `no-plottable-series`
-  refusal instead.
+  what it cannot read and uses the rest of the entry. An entry with no `field` names no column, so it
+  adds no series.
 - A `yAxis` written as a single object or a bare column name. The renderer's normalizer honours
   both as a tolerance. Neither is a member of the spec's list, and no producer on this node writes
   either, so they are refused with a remedy (the reading objectui#7690 applied to
-  `ChartSchema.yAxis`). The normalizer is unchanged.
+  `ChartSchema.yAxis`). The normalizer is unchanged. It reads a single object as a one-entry list, so
+  a single object with no `field` adds no series either.
 
 A TS consumer that typed a bare-string `xAxis` onto an `ObjectChartSchema` value no longer compiles.
 The one in-repo instance, a renderer-tolerance test fixture, now carries an explicit cast.