Detect encrypted output when client encryption is disabled

When server returns encrypted output but client didn't enable encryption,
throw clear ApiException instead of letting encrypted string leak to
downstream parsers causing fastjson syntax errors.

Detection logic: output is JsonPrimitive, length > 100, matches base64
pattern. Exception message guides users to set enableEncrypt(true).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: zhansheng.lzs

src/main/java/com/alibaba/dashscope/common/DashScopeResult.java

@@ -100,6 +100,20 @@ protected <T extends Result> T fromResponse(Protocol protocol, NetworkResponse r
           this.output = null;
         } else if (jsonObject.get(ApiKeywords.OUTPUT).isJsonObject()) {
           this.output = jsonObject.get(ApiKeywords.OUTPUT).getAsJsonObject();
+        } else if (jsonObject.get(ApiKeywords.OUTPUT).isJsonPrimitive()) {
+          // Server returned encrypted output but client didn't enable encryption
+          String outputStr = jsonObject.get(ApiKeywords.OUTPUT).getAsString();
+          if (outputStr.length() > 100 && outputStr.matches("^[A-Za-z0-9+/=]+$")) {
+            throw new ApiException(
+                Status.builder()
+                    .statusCode(400)
+                    .code("EncryptionMismatch")
+                    .message(
+                        "Server returned encrypted output but client encryption is not enabled. "
+                            + "Please set enableEncrypt(true) in your request parameters.")
+                    .build());
+          }
+          this.output = jsonObject.get(ApiKeywords.OUTPUT);
         } else {
           this.output = jsonObject.get(ApiKeywords.OUTPUT);
         }