Environment-only configuration: Remove hardcoded tag IDs and fix Paperless redirect

- Remove hardcoded defaults from PAPERLESS_*_TAG_ID in settings.py
- Fix Paperless document redirect to include /paperless/ prefix and /details/ suffix
- Update footer to v2.1.3 with deer icon
- Requires PAPERLESS_DESTINATAERE_TAG_ID, PAPERLESS_LAND_TAG_ID, PAPERLESS_ADMIN_TAG_ID in environment

app/stiftung/views.py

@@ -244,7 +244,7 @@ def paperless_document_redirect(_request, doc_id: int):
     if not url:
         return Response({"error": "Paperless API not configured"}, status=400)
     base_url = url.rstrip("/api") if url.endswith("/api") else url
-    return redirect(f"{base_url}/documents/{doc_id}/")
+    return redirect(f"{base_url}/paperless/documents/{doc_id}/details/")
 
 
 @api_view(["GET"])