chore(spec): regenerate api-surface / export-origins / references for deriveColumnSummary and the ColumnSummary describe

Regenerated by `check:generated --fix` after the merge was committed
(api-surface/ui.json + export-origins/ui.json: the new export;
content/docs/references/ui/view.mdx: the ColumnSummarySchema describe).

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01H2oQebDDxYKfWZusyd8GXk

Author: os-justin

content/docs/references/ui/view.mdx

@@ -127,7 +127,7 @@ Compound-cell prefix configuration
 
 ## ColumnSummary
 
-Aggregation function for the column footer summary — and, on a grouped list view, the per-group header summary (server-side): count (COUNT(*), the group count), count_unique (count_distinct), sum, avg, min, max map onto the query AST's AggregationFunction; count_empty, count_filled, percent_empty, percent_filled have no counterpart yet and are refused loudly by the group-header compiler (an open contract question) — never dropped silently
+Aggregation function for the column footer summary — and, on a grouped list view, the per-group header summary (server-side): count (COUNT(*), the group count), count_unique (count_distinct), sum, avg, min, max map onto the query AST's AggregationFunction; count_filled, count_empty, percent_filled, percent_empty derive from one COUNT(field) node (the non-null count) and the group count — count_filled = COUNT(field), count_empty = count − COUNT(field), percent_filled = COUNT(field) / count (0 when count is 0), percent_empty = 1 − percent_filled. Server-side "empty" is null on every face; the footer's client-side reading of empty strings and empty arrays as empty is the renderer's to converge
 
 ### Allowed Values
 

packages/spec/api-surface/ui.json

@@ -427,6 +427,7 @@
     "defineReport (function)",
     "defineView (function)",
     "defineViewItem (function)",
+    "deriveColumnSummary (function)",
     "diagnoseViewMetadata (function)",
     "expandViewContainer (function)",
     "expandViewContainerWithDiagnostics (function)",

packages/spec/export-origins/ui.json

@@ -427,6 +427,7 @@
     "defineReport": "src/ui/report.zod.ts#defineReport (function)",
     "defineView": "src/ui/view.zod.ts#defineView (function)",
     "defineViewItem": "src/ui/view.zod.ts#defineViewItem (function)",
+    "deriveColumnSummary": "src/ui/view-grouping-query.ts#deriveColumnSummary (function)",
     "diagnoseViewMetadata": "src/ui/view.zod.ts#diagnoseViewMetadata (function)",
     "expandViewContainer": "src/ui/view.zod.ts#expandViewContainer (function)",
     "expandViewContainerWithDiagnostics": "src/ui/view.zod.ts#expandViewContainerWithDiagnostics (function)",