fix(labs): drop the printed range text when an edit retires the conversion

Changing the value of a converted reading cleared sourceValue and
sourceUnit but kept the printed range text, which is written in the
report's unit. With the unit gone every reader presented it as the marker
unit's window, beside numbers in another unit. The text now goes with the
conversion record (a whole-form echo of it does not bring it back); the
bounds, already converted into the marker's unit, stay.

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

@@ -192,6 +192,9 @@ export const PUT = apiHandler(
     const data: Record<string, unknown> = {};
     if (d.panel !== undefined) data.panel = d.panel;
     if (d.analyte !== undefined) data.analyte = d.analyte;
+    // Set when a changed value retires a conversion whose printed range text is
+    // in the report's unit (see below).
+    let dropPrintedText = false;
     if (d.value !== undefined) {
       data.value = d.value;
       // A number the person typed is no longer the conversion of what the
@@ -205,6 +208,18 @@ export const PUT = apiHandler(
       ) {
         data.sourceValue = null;
         data.sourceUnit = null;
+        // The printed range text belonged to the printed value and is written
+        // in the report's unit. With `sourceUnit` gone nothing would say so,
+        // and every reader would present it as the marker unit's window, so
+        // it goes with the record. The bounds stay: they were converted with
+        // the value and are already in the marker's unit.
+        if (
+          existing.sourceUnit !== null &&
+          existing.sourceReferenceText !== null
+        ) {
+          data.sourceReferenceText = null;
+          dropPrintedText = true;
+        }
       }
     }
     // v1.18.9 — qualitative edit. A row stays single-typed: editing `value` on a
@@ -220,7 +235,15 @@ export const PUT = apiHandler(
     if (d.sourceReferenceHigh !== undefined) {
       data.sourceReferenceHigh = d.sourceReferenceHigh;
     }
-    if (d.sourceReferenceText !== undefined) {
+    // A whole-form echo of the old printed text does not bring it back once the
+    // value change retired it; a text that differs is a new statement and wins.
+    if (
+      d.sourceReferenceText !== undefined &&
+      !(
+        dropPrintedText &&
+        d.sourceReferenceText === existing.sourceReferenceText
+      )
+    ) {
       data.sourceReferenceText = d.sourceReferenceText;
     }
     if (d.takenAt !== undefined) data.takenAt = d.takenAt;