test(metadata-protocol): re-measure the tombstone census on the merged tree

Merging `origin/main` moved the served registry underneath this card's
readings. #17751 retired `ChartConfigSchema.aria` and `ReportChart.aria`, so
the strip now drops one more node inside `dashboard.widgets[].chartConfig` and
two in a type that carried none before.

Re-measured with the same harness the census was taken with — the real
`getMetaTypes()` over a stub engine, counting every property whose subschema
admits no instance, with the emitter's strip stage ablated for the pre-strip
leg:

  - whole served registry, pre-strip: 80 nodes across 16 types (was 77 across
    15 at `1bdbf82cb5`) — `dashboard` 8 -> 9, and `report` 0 -> 2;
  - zod's default (output) arm alone: 77 across 15 (was 74 across 14). The
    3-node gap to the served figure is still `action`'s `io: 'input'` retry;
  - served payload after the strip: 0, unchanged — the fix still holds.

The over-drop guard's non-vacuity ledger gains the one new `dashboard` path it
is there to notice. That assertion failing is the guard working: it is the
only thing in this file that reads a concrete removal set.

The changeset sentence is re-anchored to `74eaab8614` rather than kept at
`1bdbf82cb5`. Both readings are true of their own tree, but the parenthetical
calls the sha "this change's merge base" and that is now `74eaab8614`; and a
merge-base sha is a main-line commit that survives the squash landing, where a
branch merge commit would name a sha no reader can ever check out.

Claude-Session: https://claude.ai/code/session_01KB5PFtxuy1x3dcR5gxudx6
Co-authored-by: Claude <noreply@anthropic.com>

Author: claude

.changeset/17502-served-schema-drops-unauthorable-columns.md

@@ -22,9 +22,9 @@ would put a second hand-written spelling of "this is a tombstone" in a consumer.
 A property that admits nothing and is `required` is kept: dropping it would turn
 "this object admits nothing" into "this object admits anything".
 
-Measured over the whole served registry at `1bdbf82cb5`, this change's merge
+Measured over the whole served registry at `74eaab8614`, this change's merge
 base (`@objectstack/spec` SOURCE at 17.4.0, plus the retirements unreleased at
-that sha — not the published release): 77 such nodes across 15 types — a
+that sha — not the published release): 80 such nodes across 16 types — a
 reading taken at that tree, not a standing invariant; it moves as retired keys
 land or age out.
 

packages/metadata-protocol/src/protocol.meta-types-unauthorable-columns.test.ts

@@ -16,8 +16,8 @@
  * tombstone in a row shape became a column an author is invited to fill and
  * `saveMetaItem` then refuses.
  *
- * Measured on `origin/main` at 1bdbf82cb5 over the whole served registry:
- * **77 tombstone nodes across 15 types**. Five of them are `dashboard.widgets[]`'s
+ * Measured on `origin/main` at 74eaab8614 over the whole served registry:
+ * **80 tombstone nodes across 16 types**. Five of them are `dashboard.widgets[]`'s
  * `actionUrl`, `actionType`, `actionIcon`, `responsive` and `aria` — the row
  * this file pins, and the carrier the card was filed on. ⚠️ They are not the
  * whole reachable set: a repeater row in another type reaches an author the
@@ -289,17 +289,20 @@ describe('#17502 — the served repeater row offers no column the parse door ref
             'dashboard.properties.refreshInterval',
             'dashboard.properties.aria',
             'dashboard.properties.performance',
+            // [#17751, arrived with main] `ChartConfigSchema.aria` retired one
+            // level deeper than the widget row, inside `chartConfig`.
+            'dashboard.properties.widgets.items.properties.chartConfig.properties.aria',
         ].sort());
     });
 
     // ⚠️ This control derives with zod's DEFAULT (output) arm only, which is
-    // 74 nodes across 14 types. The served payload carries 77 across 15: for
+    // 77 nodes across 15 types. The served payload carries 80 across 16: for
     // `action` alone `toJsonSchemaSafe` falls through to the `io: 'input'`
     // retry (#17501), and that arm adds `execute` / `shortcut` / `bulkEnabled`.
-    // The class guard above runs over the SERVED document and covers all 77;
+    // The class guard above runs over the SERVED document and covers all 80;
     // this control deliberately does not re-spell `isDegenerateDerivation`,
     // whose only copy belongs in the emitter.
-    it('control: the class really is non-empty before the strip — 74 nodes across 14 types on the output arm', () => {
+    it('control: the class really is non-empty before the strip — 77 nodes across 15 types on the output arm', () => {
         const byType = new Map<string, number>();
         for (const type of SERVED_TYPES) {
             const before = preStripDerivation(type);