fix: send explicit User-Agent (Cloudflare 403s default Python-urllib UA at id.shre.ai)

Co-Authored-By: Claude Fable 5 <[email protected]>

server/granthi_link.py

@@ -69,6 +69,8 @@ def http_json(method, url, headers=None, body=None, timeout=20):
     """Minimal JSON-over-HTTP helper. Returns (status, parsed_or_text)."""
     data = None
     hdrs = dict(headers or {})
+    # Cloudflare in front of id.shre.ai 403s the default Python-urllib UA.
+    hdrs.setdefault("User-Agent", f"granthi-link/{VERSION}")
     if body is not None:
         data = json.dumps(body).encode()
         hdrs.setdefault("Content-Type", "application/json")