fix(labs): refuse a reading whose unit differs from its marker's

A numeric lab reading was stored with its value as received and the marker's
unit stamped on it, so 5.6 mmol/L against a marker kept in mg/dL became
5.6 mg/dL and read as far below range. Both the manual/API write and the
scan commit did this; nothing compared the two units.

- POST /api/labs returns 422 labs.unit.mismatch, with the marker's unit and
  the reading's unit in meta, and writes nothing. The unit is compared only
  when one was sent: on the biomarkerId path it may be omitted, and the
  marker's unit is then the stated one. A qualitative reading has no unit.
- The scan commit skips such a row with reason unit_mismatch, so the outcome
  reads partial or failed instead of a clean save, and the toast names the
  analytes concerned rather than saying "duplicates".
- The extract response carries the matched marker's unit. The review screen
  shows a calm badge on a row in another unit, starts it unticked like a
  duplicate, and treats it as a blocking error on the unit field if it is
  ticked anyway.
- A small lab-specific normaliser forgives spelling only: spacing, the micro
  prefix, the case of the litre, and a unit printed in capitals for a short
  list where capitals cannot mean another unit. Case is otherwise significant,
  so mIU/L and MIU/L, or g/L and G/L, are never merged.

The document-commit path already refuses a mismatch and is left as it is.
Readings stored wrongly before this cannot be identified, because the
original unit was never kept; they are not touched.

Adds EN and DE strings; the other locales are left to the maintainers. The
OpenAPI spec and the error-code catalogue carry the new code.

Fixes #1094

docs/api/openapi.yaml

@@ -14063,7 +14063,16 @@ paths:
         "401": *a1
         "403": *a10
         "409": *a7
-        "422": *a4
+        "422":
+          description: Nothing was written. `meta.errorCode` = `labs.create.invalid` when the body failed validation (every issue
+            under `details.issues`), or `labs.unit.mismatch` when a numeric reading states a `unit` other than the one
+            its marker is tracked in (`meta.markerUnit`, `meta.readingUnit`). A unit is compared only when one is sent;
+            with a `biomarkerId` it may be omitted and the marker's unit is then the stated one. Spelling is forgiven
+            (`mmol/l`, `ug/L` for `µg/L`); a different unit is refused, never relabelled.
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/ErrorEnvelope"
         "429": *a11
   /api/labs/{id}:
     get:
@@ -14264,9 +14273,9 @@ paths:
         - Labs
       summary: Commit confirmed Lab-OCR rows
       description: 'Writes ONLY the rows the human confirmed on the review screen. Each row resolves-or-mints a user-scoped
-        biomarker and creates a `LabResult` with `source: "OCR"`; a row that duplicates a live reading is skipped.
-        Idempotent (Idempotency-Key). Audits as `labs.ocr.commit`. `userId` is narrowed from the session, never a body
-        field.'
+        biomarker and creates a `LabResult` with `source: "OCR"`; a row that duplicates a live reading, or states a unit
+        other than that of its marker, is skipped (`skipped[].reason`). Idempotent (Idempotency-Key). Audits as
+        `labs.ocr.commit`. `userId` is narrowed from the session, never a body field.'
       parameters:
         - *a6
       requestBody:
@@ -31757,15 +31766,16 @@ components:
                 labs.biomarker.notFound, labs.biomarker.update.invalid, labs.biomarker.update.referenceRangeInvalid,
                 labs.create.invalid, labs.ocr.budgetExceeded, labs.ocr.extractFailed, labs.ocr.fileTooLarge,
                 labs.ocr.fileType, labs.ocr.localOcrDisabled, labs.ocr.pdfNeedsAnthropic, labs.ocr.providerUnsupported,
-                labs.ocr.rateLimited, labs.restore.invalid, labs.result.notFound, labs.update.invalid,
-                labs.update.linkedFieldsImmutable, labs.update.numericExpected, labs.update.qualitativeExpected,
-                labs.update.referenceRangeInvalid, labs.update.sourceReferenceRangeInvalid; managed_profile —
-                managed_profile.guardian.duplicate, managed_profile.guardian.managed_invitee,
-                managed_profile.guardian.required, managed_profile.not_found; measurement — measurement.batch.invalid,
-                measurement.batch.source_not_permitted, measurement.batch.too_large, measurement.bulk-delete.invalid,
-                measurement.create.invalid, measurement.create.source_not_permitted, measurement.delete.too_large,
-                measurement.duplicate_timestamp, measurement.restore.invalid, measurement.update.server_owned_source;
-                medication — medication.intake.import.invalid_format; medications —
+                labs.ocr.rateLimited, labs.restore.invalid, labs.result.notFound, labs.unit.mismatch,
+                labs.update.invalid, labs.update.linkedFieldsImmutable, labs.update.numericExpected,
+                labs.update.qualitativeExpected, labs.update.referenceRangeInvalid,
+                labs.update.sourceReferenceRangeInvalid; managed_profile — managed_profile.guardian.duplicate,
+                managed_profile.guardian.managed_invitee, managed_profile.guardian.required, managed_profile.not_found;
+                measurement — measurement.batch.invalid, measurement.batch.source_not_permitted,
+                measurement.batch.too_large, measurement.bulk-delete.invalid, measurement.create.invalid,
+                measurement.create.source_not_permitted, measurement.delete.too_large, measurement.duplicate_timestamp,
+                measurement.restore.invalid, measurement.update.server_owned_source; medication —
+                medication.intake.import.invalid_format; medications —
                 medications.intake.bulk.apple_health_not_mirrored, medications.intake.bulk.invalid,
                 medications.intake.bulk.too_large, medications.intake.force_slot.invalid,
                 medications.intake.force_slot.occupied, medications.intake.injection_site.disallowed,
@@ -63372,6 +63382,13 @@ components:
           enum:
             - new
             - existing
+        markerUnit:
+          anyOf:
+            - type: string
+            - type: "null"
+          description: "The unit the matched marker is tracked in, or null when the marker does not exist yet (it will adopt this
+            row's unit). A row whose `unit` differs from it cannot be committed: the commit skips it with `reason:
+            unit_mismatch`, and the review screen marks it before Save."
         duplicateOf:
           anyOf:
             - type: string
@@ -63387,6 +63404,7 @@ components:
         - takenAt
         - confidence
         - biomarkerMatch
+        - markerUnit
         - duplicateOf
       additionalProperties: false
       description: "One proposed reading transcribed from the upload. UNTRUSTED model output annotated server-side:
@@ -63427,7 +63445,11 @@ components:
                 type: string
               reason:
                 type: string
-                const: duplicate
+                enum:
+                  - duplicate
+                  - unit_mismatch
+                description: "`duplicate`: the row matched a live reading at commit time. `unit_mismatch`: the row states a unit other
+                  than the one its marker is tracked in, so it was not written."
             required:
               - analyte
               - reason
@@ -63447,7 +63469,8 @@ components:
         - skipped
         - outcome
       additionalProperties: false
-      description: 'The rows written (`source: "OCR"`), those skipped as commit-time duplicates, and the resolved outcome.'
+      description: 'The rows written (`source: "OCR"`), those skipped (commit-time duplicates, or a unit that differs from
+        that of the marker), and the resolved outcome.'
     OcrCommittedLabResult:
       type: object
       properties: