perf(medications): stop re-sending the read a nav prefetch just made

The medications list and the compliance summary refetch on every mount,
so a take or skip logged on another device shows on return (#316). The
nav link's hover / touch / focus intent and the route-commit preload
prefetch both reads too, so every visit through a link sent each of
them twice: the prefetch, then the identical request from the mount a
few hundred milliseconds after the first answer landed.

The mount now skips its refetch only when the cached data answers a
prefetch that went to the network for this visit: within the last 10 s,
and since the route last left /medications. A direct load, a return
with an older entry, or a quick return whose prefetch found the entry
still fresh keep the refetch on mount.

src/components/providers.tsx

@@ -34,7 +34,10 @@ import {
   getRecordSessionTransition,
   subscribeToRecordSessionTransition,
 } from "@/lib/query-keys/record-session-transition";
-import { prefetchMedicationsList } from "@/lib/queries/prefetch-medications";
+import {
+  forgetMedicationsPrefetch,
+  prefetchMedicationsList,
+} from "@/lib/queries/prefetch-medications";
 import {
   getRecordScope,
   subscribeToRecordScope,
@@ -245,6 +248,10 @@ function DashboardSnapshotPreloader() {
     // intent, so this is the fallback for direct loads + reloads.
     if (pathname === "/medications") {
       prefetchMedicationsList(queryClient, controller.signal);
+    } else {
+      // Off the page: a later prefetch starts a new visit, and an earlier one
+      // must not excuse the next mount's re-verification.
+      forgetMedicationsPrefetch();
     }
     // A transition to an unresolved, refused, or different record scope must
     // abort a preloader before its response can be adopted by the next route.