fix(labs): shared primitives in lab views, drop value Learn link

Replace the hand-rolled native scan dropzone button with the shared
Button primitive, swap the inline-style chart height for a height
class, and remove the Learn link from the biomarker value view where it
does not belong.

src/components/labs/lab-biomarker-chart.tsx

@@ -14,7 +14,6 @@ import {
 } from "recharts";
 
 import { Button } from "@/components/ui/button";
-import { CHART_HEIGHT_PX } from "@/lib/charts/constants";
 import { prefersReducedMotion } from "@/lib/charts/reduced-motion";
 import { formatDateShort } from "@/lib/format";
 import { formatLabValue } from "@/lib/labs/format-value";
@@ -128,7 +127,7 @@ export function LabBiomarkerChart({
           {t("labs.chart.empty")}
         </p>
       ) : (
-        <div style={{ height: CHART_HEIGHT_PX }}>
+        <div className="h-[240px]">
           <ResponsiveContainer width="100%" height="100%">
             <ComposedChart
               data={points}

src/components/labs/lab-biomarker-detail.tsx

@@ -11,7 +11,6 @@ import { Button } from "@/components/ui/button";
 import { Card, CardContent } from "@/components/ui/card";
 import { EmptyState } from "@/components/ui/empty-state";
 import { ResponsiveSheet } from "@/components/ui/responsive-sheet";
-import { LearnMoreLink } from "@/components/ui/learn-more-link";
 import { Skeleton } from "@/components/ui/skeleton";
 import { apiDelete, apiGet } from "@/lib/api/api-fetch";
 import { classifyReferenceRange } from "@/lib/labs/reference-range";
@@ -228,8 +227,6 @@ export function LabBiomarkerDetail({ biomarkerId }: { biomarkerId: string }) {
         <p className="text-muted-foreground text-sm">{marker.context}</p>
       ) : null}
 
-      <LearnMoreLink concept="LAB_BIOMARKER" />
-
       <Card>
         <CardContent className="pt-6">
           {isLoading ? (

src/components/labs/ocr-review-dialog.tsx

@@ -220,11 +220,12 @@ export function OcrReviewDialog({
               if (file) onFilePicked(file);
             }}
           />
-          <button
+          <Button
             type="button"
+            variant="outline"
             onClick={() => inputRef.current?.click()}
             disabled={extract.isPending}
-            className="border-muted-foreground/25 hover:bg-muted/50 focus-visible:ring-ring flex min-h-44 w-full flex-col items-center justify-center gap-3 rounded-lg border border-dashed p-6 text-center transition-colors focus-visible:ring-2 focus-visible:outline-none disabled:opacity-60"
+            className="border-muted-foreground/25 hover:bg-muted/50 h-auto min-h-44 w-full flex-col gap-3 rounded-lg border-dashed p-6 text-center whitespace-normal"
           >
             {extract.isPending ? (
               <>
@@ -261,7 +262,7 @@ export function OcrReviewDialog({
                 ) : null}
               </>
             )}
-          </button>
+          </Button>
         </div>
       ) : (
         <div className="space-y-3 py-2">