fix(labs): word a value without a unit the same on every remaining surface

The briefing's lab input passed the stored "1" to the model, the unit
mismatch refusal read "is in 1", and the trend card left a gap where a
language puts the unit before a particle. get_labs says that a value
without a unit has an empty unit, and a lab link id is scrubbed like its
label. The review row is back at its baseline length.

src/__tests__/baselines/source-function-lines.json

@@ -1,7 +1,7 @@
 {
   "$comment": "Production functions over 200 lines, keyed \"file :: name\", and their length. Maintained by src/__tests__/source-size-ratchet.test.ts.",
   "count": 345,
-  "total": 111930,
+  "total": 111929,
   "entries": {
     "app/achievements/page.tsx :: AchievementsPage": 206,
     "app/api/admin/backups/upload/route.ts :: apiHandler(arg)": 275,
@@ -93,7 +93,7 @@
     "components/documents/document-card.tsx :: DocumentCard": 354,
     "components/documents/document-detail-sheet.tsx :: DocumentDetailSheet": 325,
     "components/documents/document-facts-review.tsx :: DocumentFactsSection": 242,
-    "components/documents/document-facts-review.tsx :: FactRow": 263,
+    "components/documents/document-facts-review.tsx :: FactRow": 262,
     "components/documents/document-filter-bar.tsx :: DocumentFilterBar": 348,
     "components/documents/document-record-links.tsx :: DocumentRecordLinks": 202,
     "components/documents/document-timeline.tsx :: DocumentTimeline": 314,