fix: set qrcut upload User-Agent for Cloudflare

hf_dashboard.py

@@ -243,6 +243,8 @@ def _upload_public_png(*, image: Image.Image, object_path: str, max_size: int |
                     "X-QRCUT-WRITE-KEY": QRCUT_WRITE_API_KEY,
                     "Content-Type": "image/png",
                     "X-Upsert": "true",
+                    "User-Agent": "AI-QR-Code-Generator/1.0 (+https://huggingface.co/spaces/Oysiyl/AI-QR-code-generator)",
+                    "Accept": "application/json, text/plain, */*",
                 },
                 method="PUT",
             )
@@ -256,6 +258,12 @@ def _upload_public_png(*, image: Image.Image, object_path: str, max_size: int |
                         f"[qrcut] dual-write HTTP {kvm_resp.status}: {object_path} body={response_body}",
                         flush=True,
                     )
+        except urllib_error.HTTPError as exc:
+            response_body = exc.read(400).decode("utf-8", errors="replace").strip()
+            print(
+                f"[qrcut] dual-write failed HTTP {exc.code}: {exc.reason} body={response_body} -- {object_path}",
+                flush=True,
+            )
         except (urllib_error.URLError, TimeoutError, OSError) as exc:
             print(f"[qrcut] dual-write failed: {exc} -- {object_path}", flush=True)
     else: