feat: bouton télécharger et remplacer + fix extraction volumes UTF-8

- Ajout d'un bouton "télécharger et remplacer" avec popup de
  confirmation, qui passe tous les volumes du pack (pas seulement
  les manquants) et replace_existing=true à l'API.
- Nouvelle colonne replace_existing dans torrent_downloads.
- Fix critique du parseur de volumes : le pass 2 mélangeait les
  indices d'octets (String::find) avec les indices de caractères
  (Vec<char>), causant un décalage quand le titre contenait des
  caractères multi-octets (é, à...). "Tome #097" extrayait 9
  au lieu de 97. Réécrit en indexation char pure.
- Le préfixe "tome" skip désormais "#" (tome #097 → 97).
- Protection intra-batch : si une destination est déjà utilisée,
  le fichier garde son nom original au lieu d'écraser.
- Alerte WARN si N fichiers source donnent N/3 volumes uniques.
- Nettoyage du répertoire sl-{id} et de la catégorie qBittorrent
  après import.
- Badges volumes en flex-wrap dans la page downloads.

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

apps/backoffice/app/components/QbittorrentDownloadButton.tsx

@@ -1,7 +1,8 @@
 "use client";
 
 import { useState, useEffect, createContext, useContext, type ReactNode } from "react";
-import { Icon } from "./ui";
+import { createPortal } from "react-dom";
+import { Icon, Button } from "./ui";
 import { useTranslation } from "@/lib/i18n/context";
 
 interface QbContextValue {
@@ -34,22 +35,28 @@ export function QbittorrentDownloadButton({
   libraryId,
   seriesName,
   expectedVolumes,
+  allVolumes,
 }: {
   downloadUrl: string;
   releaseId: string;
   libraryId?: string;
   seriesName?: string;
   expectedVolumes?: number[];
+  allVolumes?: number[];
 }) {
   const { t } = useTranslation();
   const { configured, onDownloadStarted } = useContext(QbConfigContext);
   const [sending, setSending] = useState(false);
   const [sent, setSent] = useState(false);
   const [error, setError] = useState<string | null>(null);
+  const [showConfirm, setShowConfirm] = useState(false);
 
   if (!configured) return null;
 
-  async function handleSend() {
+  const hasExistingVolumes = allVolumes && expectedVolumes
+    && allVolumes.length > expectedVolumes.length;
+
+  async function handleSend(volumes?: number[], replaceExisting = false) {
     setSending(true);
     setError(null);
     try {
@@ -60,7 +67,8 @@ export function QbittorrentDownloadButton({
           url: downloadUrl,
           ...(libraryId && { library_id: libraryId }),
           ...(seriesName && { series_name: seriesName }),
-          ...(expectedVolumes && { expected_volumes: expectedVolumes }),
+          ...((volumes || expectedVolumes) && { expected_volumes: volumes || expectedVolumes }),
+          ...(replaceExisting && { replace_existing: true }),
         }),
       });
       const data = await resp.json();
@@ -81,28 +89,71 @@ export function QbittorrentDownloadButton({
   }
 
   return (
-    <button
-      type="button"
-      onClick={handleSend}
-      disabled={sending}
-      className={`inline-flex items-center justify-center w-7 h-7 rounded-md transition-colors disabled:opacity-50 shrink-0 ${
-        sent
-          ? "text-green-500"
-          : error
-            ? "text-destructive"
-            : "text-primary hover:bg-primary/10"
-      }`}
-      title={sent ? t("prowlarr.sentSuccess") : error || t("prowlarr.sendToQbittorrent")}
-    >
-      {sending ? (
-        <Icon name="spinner" size="sm" className="animate-spin" />
-      ) : sent ? (
-        <svg width="14" height="14" viewBox="0 0 16 16" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
-          <path d="M3 8l4 4 6-7" />
-        </svg>
-      ) : (
-        <Icon name="download" size="sm" />
+    <>
+      <div className="inline-flex items-center gap-0.5">
+        <button
+          type="button"
+          onClick={() => handleSend()}
+          disabled={sending}
+          className={`inline-flex items-center justify-center w-7 h-7 rounded-md transition-colors disabled:opacity-50 shrink-0 ${
+            sent
+              ? "text-green-500"
+              : error
+                ? "text-destructive"
+                : "text-primary hover:bg-primary/10"
+          }`}
+          title={sent ? t("prowlarr.sentSuccess") : error || t("prowlarr.sendToQbittorrent")}
+        >
+          {sending ? (
+            <Icon name="spinner" size="sm" className="animate-spin" />
+          ) : sent ? (
+            <svg width="14" height="14" viewBox="0 0 16 16" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+              <path d="M3 8l4 4 6-7" />
+            </svg>
+          ) : (
+            <Icon name="download" size="sm" />
+          )}
+        </button>
+
+        {hasExistingVolumes && (
+          <button
+            type="button"
+            onClick={() => setShowConfirm(true)}
+            disabled={sending}
+            className="inline-flex items-center justify-center w-7 h-7 rounded-md transition-colors disabled:opacity-50 shrink-0 text-warning hover:bg-warning/10"
+            title={t("prowlarr.replaceAndDownload")}
+          >
+            <Icon name="refresh" size="sm" />
+          </button>
+        )}
+      </div>
+
+      {showConfirm && createPortal(
+        <>
+          <div className="fixed inset-0 bg-black/30 backdrop-blur-sm z-50" onClick={() => setShowConfirm(false)} />
+          <div className="fixed inset-0 flex items-center justify-center z-50 p-4">
+            <div className="bg-card border border-border/50 rounded-xl shadow-2xl w-full max-w-sm overflow-hidden animate-in fade-in zoom-in-95 duration-200">
+              <div className="p-6">
+                <h3 className="text-lg font-semibold text-foreground mb-2">
+                  {t("prowlarr.replaceAndDownload")}
+                </h3>
+                <p className="text-sm text-muted-foreground">
+                  {t("prowlarr.confirmReplace")}
+                </p>
+              </div>
+              <div className="flex justify-end gap-2 px-6 pb-6">
+                <Button variant="outline" size="sm" onClick={() => setShowConfirm(false)}>
+                  {t("common.cancel")}
+                </Button>
+                <Button variant="destructive" size="sm" onClick={() => { setShowConfirm(false); handleSend(allVolumes, true); }}>
+                  {t("prowlarr.replaceAndDownload")}
+                </Button>
+              </div>
+            </div>
+          </div>
+        </>,
+        document.body
       )}
-    </button>
+    </>
   );
 }