feat(labs): record qualitative lab results

Add first-class qualitative lab findings (positive / negative / borderline
serology) alongside the existing numeric path. A LabResult is now EITHER a
numeric reading (value + unit, optional reference bounds) OR a qualitative one
(valueText, e.g. "negativ"), never both, never neither.

- schema: make `value` nullable, add `value_text`; migration 0181 is additive
  (DROP NOT NULL + ADD COLUMN), every existing numeric row is untouched.
- validation: numeric-XOR-qualitative refine on create + update; unit/bounds
  apply to the numeric path only; valueText capped at 120 chars. The single
  resource PUT rejects a cross-type edit.
- serialise: carry valueText through both DTOs; a qualitative row reports the
  neutral `unknown` range verdict (no number to classify).
- FHIR: a qualitative result emits valueCodeableConcept — SNOMED qualifier
  value for confidently-known terms (Negative 260385009, Positive 10828004,
  Not detected 260415000, Detected 260373001), text-only for borderline /
  grenzwertig and any unrecognised term. The raw text always rides .text.
- UI: a numeric/qualitative toggle in the lab form; list, history, detail,
  chart, sparkline, and the doctor-report PDF all render qualitative readings
  as their text and never plot or divide on a null value.
- i18n: new labs.form keys across all six locales.
- openapi: response carries a nullable value + valueText; regenerated.

src/app/api/labs/[id]/route.ts

@@ -150,6 +150,24 @@ export const PUT = apiHandler(
       );
     }
 
+    // v1.18.9 — a row keeps its type. Editing `value` on a qualitative row or
+    // `valueText` on a numeric row would either leave both columns populated or
+    // strand the row in an ambiguous state. Reject the cross-type edit with a
+    // 422 — switch types by deleting and re-adding.
+    const rowIsQualitative = existing.valueText !== null;
+    if (rowIsQualitative && d.value !== undefined) {
+      return apiError(
+        "This is a qualitative reading — edit its result text, not a numeric value",
+        422,
+      );
+    }
+    if (!rowIsQualitative && d.valueText !== undefined) {
+      return apiError(
+        "This is a numeric reading — edit its value, not a qualitative result",
+        422,
+      );
+    }
+
     // Build `data` field-by-field. `undefined` → leave the column untouched;
     // an explicit `null` on `panel` / `note` / a reference bound clears it.
     // A reading linked to a catalog marker is edited via VALUE / takenAt /
@@ -158,6 +176,10 @@ export const PUT = apiHandler(
     if (d.panel !== undefined) data.panel = d.panel;
     if (d.analyte !== undefined) data.analyte = d.analyte;
     if (d.value !== undefined) data.value = d.value;
+    // v1.18.9 — qualitative edit. A row stays single-typed: editing `value` on a
+    // qualitative row (or `valueText` on a numeric row) crosses the row's type
+    // and is rejected below. An edit of the matching field updates in place.
+    if (d.valueText !== undefined) data.valueText = d.valueText;
     if (d.unit !== undefined) data.unit = d.unit;
     if (d.referenceLow !== undefined) data.referenceLow = d.referenceLow;
     if (d.referenceHigh !== undefined) data.referenceHigh = d.referenceHigh;

src/app/api/labs/route.ts

@@ -173,6 +173,7 @@ async function postLabResult(request: NextRequest) {
     panel,
     analyte,
     value,
+    valueText,
     unit,
     referenceLow,
     referenceHigh,
@@ -180,6 +181,10 @@ async function postLabResult(request: NextRequest) {
     note,
   } = parsed.data;
 
+  // v1.18.9 — a qualitative reading carries `valueText` ("negativ" / …) instead
+  // of a number. The Zod refine guarantees exactly one of the two is present.
+  const isQualitative = valueText !== undefined;
+
   // Every row links a catalog marker — no `LabResult` ever persists unlinked
   // (v1.18.1 High). Two paths converge on a `biomarker`:
   //  - Structured: a `biomarkerId` is supplied; resolve + verify ownership
@@ -207,9 +212,12 @@ async function postLabResult(request: NextRequest) {
   } else {
     biomarker = await resolveOrMintBiomarker(user.id, {
       analyte: analyte as string,
-      unit: unit as string,
-      referenceLow: referenceLow ?? null,
-      referenceHigh: referenceHigh ?? null,
+      // A qualitative reading has no numeric unit / range — mint the catalog
+      // marker with an empty unit label and no bounds. A numeric reading
+      // supplies its unit (Zod requires it on the free-text numeric path).
+      unit: isQualitative ? (unit ?? "") : (unit as string),
+      referenceLow: isQualitative ? null : (referenceLow ?? null),
+      referenceHigh: isQualitative ? null : (referenceHigh ?? null),
       panel: panel ?? null,
     });
   }
@@ -224,7 +232,9 @@ async function postLabResult(request: NextRequest) {
       biomarkerId: biomarker.id,
       panel: biomarker.panel,
       analyte: biomarker.name,
-      value,
+      // Exactly one of value / valueText is set (the Zod XOR refine).
+      value: value ?? null,
+      valueText: valueText ?? null,
       unit: biomarker.unit,
       referenceLow: biomarker.lowerBound,
       referenceHigh: biomarker.upperBound,