fix(HEL-412): 刷新降级不再整次失败，并补齐准备中提示

手动刷新与自动补跑共用可用数据判定：日线推算或上一交易日快照记为部分/准备中成功，避免前端误报刷新失败。HTTP JSON 解析错误不再把请求正文写入日志。

Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: multica-agent <github@multica.ai>

xiaobai-datahub/datahub/adapters/tushare.py

@@ -145,7 +145,9 @@ class TushareAdapter(MarketAdapter):
         try:
             with urllib.request.urlopen(request, timeout=self.timeout) as response:
                 result = json.loads(response.read().decode("utf-8"))
-        except (urllib.error.URLError, TimeoutError, json.JSONDecodeError) as exc:
+        except json.JSONDecodeError:
+            raise AdapterError("Tushare returned invalid json") from None
+        except (urllib.error.URLError, TimeoutError) as exc:
             raise AdapterError(f"Tushare request failed: {exc}") from exc
         if result.get("code") != 0:
             raise AdapterError(result.get("msg") or "Tushare returned an unknown error")