feat(backoffice): add reading progress management, series page, and live search

- API: add POST /series/mark-read to batch mark all books in a series
- API: add GET /series cross-library endpoint with search, library and status filters
- API: add library_id to SeriesItem response
- Backoffice: mark book as read/unread button on book detail page
- Backoffice: mark series as read/unread button on series cards
- Backoffice: new /series top-level page with search and filters
- Backoffice: new /libraries/[id]/series/[name] series detail page
- Backoffice: opacity on fully read books and series cards
- Backoffice: live search with debounce on books and series pages
- Backoffice: reading status filter on books and series pages
- Fix $2 -> $1 parameter binding in mark-series-read SQL

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/backoffice/app/components/MarkSeriesReadButton.tsx

@@ -0,0 +1,74 @@
+"use client";
+
+import { useState } from "react";
+import { useRouter } from "next/navigation";
+
+interface MarkSeriesReadButtonProps {
+  seriesName: string;
+  bookCount: number;
+  booksReadCount: number;
+}
+
+export function MarkSeriesReadButton({ seriesName, bookCount, booksReadCount }: MarkSeriesReadButtonProps) {
+  const [loading, setLoading] = useState(false);
+  const router = useRouter();
+
+  const allRead = booksReadCount >= bookCount;
+  const targetStatus = allRead ? "unread" : "read";
+  const label = allRead ? "Marquer non lu" : "Tout marquer lu";
+
+  const handleClick = async (e: React.MouseEvent) => {
+    e.preventDefault();
+    e.stopPropagation();
+    setLoading(true);
+    try {
+      const res = await fetch("/api/series/mark-read", {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({ series: seriesName, status: targetStatus }),
+      });
+      if (!res.ok) {
+        const body = await res.json().catch(() => ({ error: res.statusText }));
+        console.error("Failed to mark series:", body.error);
+      }
+      router.refresh();
+    } catch (err) {
+      console.error("Failed to mark series:", err);
+    } finally {
+      setLoading(false);
+    }
+  };
+
+  return (
+    <button
+      onClick={handleClick}
+      disabled={loading}
+      className={`inline-flex items-center gap-1 text-xs px-2 py-1 rounded-full font-medium transition-colors ${
+        allRead
+          ? "bg-green-500/15 text-green-600 dark:text-green-400 hover:bg-green-500/25"
+          : "bg-muted/50 text-muted-foreground hover:bg-primary/10 hover:text-primary"
+      } disabled:opacity-50`}
+    >
+      {loading ? (
+        <svg className="w-3.5 h-3.5 animate-spin" fill="none" viewBox="0 0 24 24">
+          <circle className="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" strokeWidth="4" />
+          <path className="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4z" />
+        </svg>
+      ) : allRead ? (
+        <>
+          <svg className="w-3.5 h-3.5" fill="none" stroke="currentColor" viewBox="0 0 24 24" strokeWidth={2}>
+            <path strokeLinecap="round" strokeLinejoin="round" d="M9 15 3 9m0 0 6-6M3 9h12a6 6 0 0 1 0 12h-3" />
+          </svg>
+          {label}
+        </>
+      ) : (
+        <>
+          <svg className="w-3.5 h-3.5" fill="none" stroke="currentColor" viewBox="0 0 24 24" strokeWidth={2}>
+            <path strokeLinecap="round" strokeLinejoin="round" d="M9 12.75 11.25 15 15 9.75M21 12a9 9 0 1 1-18 0 9 9 0 0 1 18 0z" />
+          </svg>
+          {label}
+        </>
+      )}
+    </button>
+  );
+}