fix(labs): mark un-linked lab groups and bridge biomarker detail to source reports

- Lab groups not backfilled to a catalog biomarker now carry a muted
  'not linked to a biomarker yet' affordance in both list and card views, so
  an inert row no longer reads as a broken link next to clickable neighbours.
- The biomarker detail page links to the document vault filtered to
  lab-result reports (gated on the documents module), giving a path from a
  value to its source scans. A per-value document relation remains a
  data-model follow-up.

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

@@ -9,9 +9,17 @@ import {
   useQuery,
   useQueryClient,
 } from "@tanstack/react-query";
-import { FlaskConical, ListOrdered, Pencil, Plus } from "lucide-react";
+import {
+  ArrowRight,
+  FlaskConical,
+  FolderOpen,
+  ListOrdered,
+  Pencil,
+  Plus,
+} from "lucide-react";
 import { toast } from "sonner";
 
+import { useAuth } from "@/hooks/use-auth";
 import { DeleteButton } from "@/components/data-list";
 import { Button } from "@/components/ui/button";
 import { Card, CardContent } from "@/components/ui/card";
@@ -84,6 +92,7 @@ const READINGS_PAGE_SIZE = 200;
  * it. Mirrors the measurement-detail layout.
  */
 export function LabBiomarkerDetail({ biomarkerId }: { biomarkerId: string }) {
+  const { user } = useAuth();
   const { t } = useTranslations();
   const router = useRouter();
   const queryClient = useQueryClient();
@@ -367,6 +376,22 @@ export function LabBiomarkerDetail({ biomarkerId }: { biomarkerId: string }) {
           catalog-less marker still carries a description. */}
       <p className="text-foreground text-sm leading-relaxed">{description}</p>
 
+      {/* Bridge to the source report PDFs. There is no per-value document
+          relation in the data model yet, so this links to the vault filtered
+          to lab-result documents rather than the exact scan behind one value.
+          Only when the documents module is enabled. */}
+      {user?.modules?.inboundDocuments ? (
+        <Link
+          href="/documents?kind=LAB_RESULT"
+          data-slot="lab-biomarker-documents-link"
+          className="text-muted-foreground hover:text-foreground focus-visible:ring-ring/50 inline-flex items-center gap-1.5 rounded-md text-sm transition-colors focus-visible:ring-[3px] focus-visible:outline-none"
+        >
+          <FolderOpen className="size-4" aria-hidden="true" />
+          {t("labs.documentsLink")}
+          <ArrowRight className="size-3.5" aria-hidden="true" />
+        </Link>
+      ) : null}
+
       {isLoading ? (
         <Card>
           <CardContent>

src/components/labs/lab-list.tsx

@@ -230,11 +230,17 @@ export function LabList({ onAddFirst }: { onAddFirst?: () => void } = {}) {
                       <ChevronRight className="text-muted-foreground h-4 w-4 shrink-0" />
                     </Link>
                   ) : (
+                    // Un-linked group (not backfilled to a catalog biomarker):
+                    // render inert but say so, so it doesn't read as a broken
+                    // link next to its clickable neighbours.
                     <div className="flex min-w-0 flex-1 items-center gap-3">
                       {inner}
                       <LabTrendSparkline
                         values={group.readings.map((r) => r.value)}
                       />
+                      <span className="text-muted-foreground shrink-0 text-xs italic">
+                        {t("labs.notLinkedYet")}
+                      </span>
                     </div>
                   )}
                 </div>
@@ -319,6 +325,14 @@ export function LabList({ onAddFirst }: { onAddFirst?: () => void } = {}) {
                     values={group.readings.map((r) => r.value)}
                   />
                 </div>
+                {/* Un-linked group: the header renders no link, so name the
+                    reason rather than leaving a card that silently does
+                    nothing on tap. */}
+                {!group.biomarkerId ? (
+                  <p className="text-muted-foreground text-xs italic">
+                    {t("labs.notLinkedYet")}
+                  </p>
+                ) : null}
               </CardContent>
             </Card>
           </li>