feat: add batch metadata jobs, series filters, and translate backoffice to French

- Add metadata_batch job type with background processing via tokio::spawn
- Auto-apply metadata only when single result at 100% confidence
- Support primary + fallback provider per library, "none" to opt out
- Add batch report/results API endpoints and job detail UI
- Add series_status and has_missing filters to both series listing pages
- Add GET /series/statuses endpoint for dynamic filter options
- Normalize series_metadata status values (migration 0036)
- Hide ComicVine provider tab when no API key configured
- Translate entire backoffice UI from English to French

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

apps/backoffice/app/api/metadata/batch/results/route.ts

@@ -0,0 +1,19 @@
+import { NextRequest, NextResponse } from "next/server";
+import { apiFetch, MetadataBatchResultDto } from "@/lib/api";
+
+export async function GET(request: NextRequest) {
+  try {
+    const { searchParams } = new URL(request.url);
+    const id = searchParams.get("id");
+    if (!id) {
+      return NextResponse.json({ error: "id is required" }, { status: 400 });
+    }
+    const status = searchParams.get("status") || "";
+    const params = status ? `?status=${status}` : "";
+    const data = await apiFetch<MetadataBatchResultDto[]>(`/metadata/batch/${id}/results${params}`);
+    return NextResponse.json(data);
+  } catch (error) {
+    const message = error instanceof Error ? error.message : "Failed to fetch results";
+    return NextResponse.json({ error: message }, { status: 500 });
+  }
+}