fix(service-analytics): a draft-preview dataset response describes its columns like the live one (#16097) (#16192)

`queryDataset`'s ADR-0037 P3 preview branch returned ~250 lines before the
ADR-0021 result-column enrichment, so a response over drafted seed rows carried
no `label`, `format`, `currency`, `percentScale`, `builtinAggregate` and no
`type` correction — on measure and dimension columns alike. The same dataset in
the same widget described its columns differently depending only on whether a
pending seed draft existed.

Every key that block writes is read off the authored dataset and
`sourceFieldMeta`, never off `result.rows`, so it is extracted into one
`enrichResultColumns` seam that both paths call — one rule, not a per-path copy
free to drift, the same argument #15768/#16101's `type` correction already makes
for living there.

Dimension VALUE label resolution stays skipped on the preview path on purpose;
the standing comment is narrowed to say that it is a statement about row values
and never covered the column descriptors.


Claude-Session: https://claude.ai/code/session_01XpTx2tbq3pZRYAdoGt6E6Y

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

Author: os-warren

.changeset/preview-column-enrichment.md

@@ -0,0 +1,19 @@
+---
+'@objectstack/service-analytics': patch
+---
+
+Analytics: a draft-preview dataset response now describes its columns like the live one
+
+`AnalyticsService.queryDataset`'s ADR-0037 P3 draft-preview branch returned before the
+ADR-0021 result-column enrichment ever ran, so a dataset queried while the base object had a
+pending seed draft came back with none of its column metadata: `fields[].label`, `format`,
+`currency`, `percentScale`, `builtinAggregate`, and the temporal `type` correction were all
+absent, on measure and dimension columns alike. A renderer then fell back to humanizing the
+raw measure name and guessing a percent scale from magnitude — so the same dataset in the
+same widget described its columns differently depending only on whether a pending seed draft
+existed, which is the surface an author is looking at while authoring the dataset.
+
+Every one of those keys is read off the authored dataset and the source object's field
+metadata, never off the rows, so the enrichment is now one method both paths call. Dimension
+VALUE label resolution (resolving a lookup id to a display name) stays skipped on the preview
+path deliberately: drafted seed rows reference lookups by name, so there is no id to resolve.