Reports/Export builder (CSV/XLSX), plus a security fix pass

Adds the Berichte export pipeline (/api/export/{report,events,employees})
with shared CSV/XLSX writers in lib/export.ts and lib/reports-data.ts.

Security pass alongside it: sanitize .or() search terms against PostgREST
filter injection, sanitize spreadsheet cells against CSV/Excel formula
injection, stop leaking raw DB error messages to clients, harden the
service-role client with server-only, add baseline security headers, and
bump the vulnerable nested postcss via an override.

app/api/export/events/route.ts

@@ -0,0 +1,62 @@
+import { NextResponse, type NextRequest } from "next/server";
+import { exportFilename, exportResponseHeaders, toCsv, toXlsx, type ExportColumn } from "@/lib/export";
+import { EVENT_TYPE_LABELS, type OrgLookups, type ReportEvent } from "@/lib/reports";
+import { loadEventHistory, loadOrgLookups } from "@/lib/reports-data";
+import { createClient } from "@/lib/supabase/server";
+import type { HistoryEventType } from "@/lib/supabase/types";
+
+// Full raw event-log dump — one row per employee_history entry in the
+// selected period (default: current year), every event type unless one is
+// picked, org columns resolved from each affected employee's current
+// placement (see loadEventHistory).
+export async function GET(request: NextRequest) {
+  const supabase = await createClient();
+  const {
+    data: { user },
+  } = await supabase.auth.getUser();
+  if (!user) return NextResponse.json({ error: "Nicht angemeldet." }, { status: 401 });
+
+  const { data: profile } = await supabase.from("profiles").select("role, is_active").eq("id", user.id).maybeSingle();
+  if (profile?.role !== "hr" || profile?.is_active !== true) {
+    return NextResponse.json({ error: "Nicht berechtigt." }, { status: 403 });
+  }
+
+  const params = request.nextUrl.searchParams;
+  const format = params.get("format") === "xlsx" ? "xlsx" : "csv";
+  const eventType = (params.get("eventType") as HistoryEventType) || undefined;
+  const from = params.get("from") ?? undefined;
+  const to = params.get("to") ?? undefined;
+
+  const [{ lookups }, events] = await Promise.all([
+    loadOrgLookups(supabase),
+    loadEventHistory(supabase, {
+      eventType,
+      division: params.get("division") ?? undefined,
+      location: params.get("location") ?? undefined,
+      from,
+      to,
+    }),
+  ]);
+
+  const columns = eventExportColumns(lookups);
+  const filename = exportFilename(`ereignisse-${eventType ?? "alle"}`, format);
+  const body = format === "xlsx" ? await toXlsx(events, columns, "Ereignisse") : toCsv(events, columns);
+  // TS 5.9's Uint8Array<ArrayBufferLike> vs DOM's BlobPart/ArrayBuffer<> generic
+  // mismatch (microsoft/TypeScript#59417) — a real Uint8Array works fine here.
+  return new NextResponse(new Blob([body as BlobPart]), { headers: exportResponseHeaders(filename, format) });
+}
+
+function eventExportColumns(lookups: OrgLookups): ExportColumn<ReportEvent>[] {
+  return [
+    { header: "Datum", get: (e) => e.event_date, kind: "date" },
+    { header: "Ereignistyp", get: (e) => EVENT_TYPE_LABELS[e.event_type] ?? e.event_type },
+    { header: "Vorname", get: (e) => e.first_name },
+    { header: "Nachname", get: (e) => e.last_name },
+    { header: "Position", get: (e) => e.job_title },
+    { header: "Bereich", get: (e) => lookups.divisionName.get(e.division_id) ?? "" },
+    { header: "Abteilung", get: (e) => (e.team_id ? (lookups.departmentNameByTeam.get(e.team_id) ?? "") : "") },
+    { header: "Team", get: (e) => (e.team_id ? (lookups.teamName.get(e.team_id) ?? "") : "") },
+    { header: "Standort", get: (e) => lookups.locationName.get(e.location_id) ?? "" },
+    { header: "Beschreibung", get: (e) => e.description },
+  ];
+}