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/lib/insights/feature-blocks.ts

@@ -29,6 +29,7 @@ import {
   canonicalWorkoutsInRange,
   readWorkoutsAroundRange,
 } from "@/lib/workouts/canonical-read";
+import { labUnitText } from "@/lib/labs/dimensionless";
 import { deriveBucketedTypes } from "@/lib/signals/adapters/correlation";
 import type {
   AggregatedFeatures,
@@ -434,7 +435,7 @@ export async function readLabsBriefingBlock(
       analyte: resolved.analyte,
       value: latest.value,
       valueText: latest.valueText ? sanitizeLabel(latest.valueText, 60) : null,
-      unit: resolved.unit,
+      unit: labUnitText(resolved.unit),
       rangeStatus,
       trend,
       takenAt: latest.takenAt.toISOString(),

src/lib/mcp/__tests__/__snapshots__/tools-list.write-session.snap

@@ -378,7 +378,7 @@
   {
     "name": "get_labs",
     "title": "Get lab results",
-    "description": "Fetch the user's lab results. By default returns the latest reading per biomarker over the whole record. Filtered to one named analyte, each matching marker also carries a summarised history (the newest earlier values in full, older ones as one mean / min / max / count per year). Pass history:true with an analyte to return that analyte's reading TRAJECTORY (newest first, paginated). Each reading carries its value, unit, reference range, and in-range/below/above status. Each reading (the latest, an earlier value in full, a trajectory reading; not a per-year summary) carries links: the ids of the records it is linked to (the report it was read from, the visits it is filed against), [] when none, at most 25 with linksTruncated; every linked record is described once in linkedRecords (id for fetch, kind, label, date, and for a document imported from Paperless-ngx or Papra its sourceSystem and sourceId). A document is listed only while the Documents module is on. Returns { present: false } when no labs match, and { present: false, reason: \"module_disabled\" } when the labs module is switched off.",
+    "description": "Fetch the user's lab results. By default returns the latest reading per biomarker over the whole record. Filtered to one named analyte, each matching marker also carries a summarised history (the newest earlier values in full, older ones as one mean / min / max / count per year). Pass history:true with an analyte to return that analyte's reading TRAJECTORY (newest first, paginated). Each reading carries its value, unit, reference range, and in-range/below/above status; a ratio or an index recorded without a unit has an empty unit. Each reading (the latest, an earlier value in full, a trajectory reading; not a per-year summary) carries links: the ids of the records it is linked to (the report it was read from, the visits it is filed against), [] when none, at most 25 with linksTruncated; every linked record is described once in linkedRecords (id for fetch, kind, label, date, and for a document imported from Paperless-ngx or Papra its sourceSystem and sourceId). A document is listed only while the Documents module is on. Returns { present: false } when no labs match, and { present: false, reason: \"module_disabled\" } when the labs module is switched off.",
     "inputSchema": {
       "type": "object",
       "properties": {

src/lib/mcp/record-links.ts

@@ -104,7 +104,7 @@ async function labLinks(
     const name = analyte.get(target.id);
     if (!name) continue;
     out.set(target.id, {
-      id: `lab:${name}`,
+      id: `lab:${scrubFenceMarkers(name)}`,
       kind: "lab",
       label: scrubFenceMarkers(target.label),
       date: linkDate(target.date),

src/lib/mcp/tools/get-labs.ts

@@ -140,7 +140,7 @@ export const getLabsTool: McpToolDefinition = {
   name: "get_labs",
   title: "Get lab results",
   description:
-    "Fetch the user's lab results. By default returns the latest reading per biomarker over the whole record. Filtered to one named analyte, each matching marker also carries a summarised history (the newest earlier values in full, older ones as one mean / min / max / count per year). Pass history:true with an analyte to return that analyte's reading TRAJECTORY (newest first, paginated). Each reading carries its value, unit, reference range, and in-range/below/above status. Each reading (the latest, an earlier value in full, a trajectory reading; not a per-year summary) carries links: the ids of the records it is linked to (the report it was read from, the visits it is filed against), [] when none, at most 25 with linksTruncated; every linked record is described once in linkedRecords (id for fetch, kind, label, date, and for a document imported from Paperless-ngx or Papra its sourceSystem and sourceId). A document is listed only while the Documents module is on. Returns { present: false } when no labs match, and { present: false, reason: \"module_disabled\" } when the labs module is switched off.",
+    "Fetch the user's lab results. By default returns the latest reading per biomarker over the whole record. Filtered to one named analyte, each matching marker also carries a summarised history (the newest earlier values in full, older ones as one mean / min / max / count per year). Pass history:true with an analyte to return that analyte's reading TRAJECTORY (newest first, paginated). Each reading carries its value, unit, reference range, and in-range/below/above status; a ratio or an index recorded without a unit has an empty unit. Each reading (the latest, an earlier value in full, a trajectory reading; not a per-year summary) carries links: the ids of the records it is linked to (the report it was read from, the visits it is filed against), [] when none, at most 25 with linksTruncated; every linked record is described once in linkedRecords (id for fetch, kind, label, date, and for a document imported from Paperless-ngx or Papra its sourceSystem and sourceId). A document is listed only while the Documents module is on. Returns { present: false } when no labs match, and { present: false, reason: \"module_disabled\" } when the labs module is switched off.",
   inputShape: {
     analyte: z.string().min(1).max(80).optional(),
     history: z