feat: refresh metadata ciblé par série après import et dans la modale

- Après import torrent, refresh automatique des métadonnées uniquement
  sur la série importée (via refresh_link) au lieu d'un job complet
- Nouvel endpoint POST /metadata/refresh-link/:id pour rafraîchir un
  seul lien metadata approuvé
- Bouton "Rafraîchir" dans la modale metadata (état linked) avec
  spinner et confirmation visuelle

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/backoffice/app/api/metadata/refresh-link/[id]/route.ts

@@ -0,0 +1,13 @@
+import { NextRequest, NextResponse } from "next/server";
+import { apiFetch } from "@/lib/api";
+
+export async function POST(_request: NextRequest, { params }: { params: Promise<{ id: string }> }) {
+  try {
+    const { id } = await params;
+    const data = await apiFetch(`/metadata/refresh-link/${id}`, { method: "POST" });
+    return NextResponse.json(data);
+  } catch (error) {
+    const message = error instanceof Error ? error.message : "Failed to refresh metadata";
+    return NextResponse.json({ error: message }, { status: 500 });
+  }
+}

apps/backoffice/app/components/MetadataSearchModal.tsx

@@ -55,6 +55,8 @@ export function MetadataSearchModal({
   const [missing, setMissing] = useState<MissingBooksDto | null>(initialMissing);
   const [showMissingList, setShowMissingList] = useState(false);
   const [syncReport, setSyncReport] = useState<SyncReport | null>(null);
+  const [refreshing, setRefreshing] = useState(false);
+  const [refreshDone, setRefreshDone] = useState(false);
 
   // Provider selector: empty string = library default
   const [searchProvider, setSearchProvider] = useState("");
@@ -655,6 +657,37 @@ export function MetadataSearchModal({
                       >
                         {t("metadata.searchAgain")}
                       </button>
+                      <button
+                        type="button"
+                        disabled={refreshing}
+                        onClick={async () => {
+                          if (!linkId) return;
+                          setRefreshing(true);
+                          setRefreshDone(false);
+                          try {
+                            const resp = await fetch(`/api/metadata/refresh-link/${linkId}`, { method: "POST" });
+                            if (resp.ok) {
+                              setRefreshDone(true);
+                              setTimeout(() => setRefreshDone(false), 3000);
+                            }
+                          } finally {
+                            setRefreshing(false);
+                          }
+                        }}
+                        className={`p-2.5 rounded-lg border text-sm font-medium transition-colors ${
+                          refreshDone
+                            ? "border-success/30 bg-success/5 text-success"
+                            : "border-primary/30 bg-primary/5 text-primary hover:bg-primary/10"
+                        }`}
+                      >
+                        {refreshing ? (
+                          <Icon name="spinner" size="sm" className="animate-spin" />
+                        ) : refreshDone ? (
+                          <Icon name="check" size="sm" />
+                        ) : (
+                          t("metadata.refreshLink")
+                        )}
+                      </button>
                       <button
                         type="button"
                         onClick={handleUnlink}