fix: standardize Chinese validation messages

src/main/java/com/yau/digitalrmb/platformintegration/application/PlatformTokenVerifier.java

@@ -67,7 +67,7 @@ public class PlatformTokenVerifier {
         } catch (PlatformTokenException exception) {
             throw exception;
         } catch (Exception exception) {
-            throw new PlatformTokenException("Invalid platform token", exception);
+            throw new PlatformTokenException("平台登录凭据无效", exception);
         }
     }
 
@@ -85,5 +85,5 @@ public class PlatformTokenVerifier {
     private long requiredLong(JsonNode payload, String name) { JsonNode node = payload.path(name); if (!node.canConvertToLong()) throw invalid(); return node.asLong(); }
     private String requiredText(JsonNode payload, String name) { String value = payload.path(name).asText(); if (value == null || value.trim().isEmpty()) throw invalid(); return value; }
     private String optionalText(JsonNode payload, String name) { JsonNode node = payload.path(name); return node.isMissingNode() || node.isNull() ? null : node.asText(); }
-    private PlatformTokenException invalid() { return new PlatformTokenException("Invalid platform token"); }
+    private PlatformTokenException invalid() { return new PlatformTokenException("平台登录凭据无效"); }
 }

src/main/java/com/yau/digitalrmb/shared/web/GlobalExceptionHandler.java

@@ -22,7 +22,7 @@ public class GlobalExceptionHandler {
     @ExceptionHandler({ConstraintViolationException.class, MethodArgumentNotValidException.class})
     @ResponseStatus(HttpStatus.BAD_REQUEST)
     public ApiResponse<Void> handleValidation(Exception exception) {
-        return ApiResponse.failure(ErrorCode.VALIDATION_ERROR, exception.getMessage(), traceId());
+        return ApiResponse.failure(ErrorCode.VALIDATION_ERROR, "请求参数校验失败", traceId());
     }
 
     @ExceptionHandler(BusinessException.class)

src/test/java/com/yau/digitalrmb/shared/GlobalExceptionHandlerTest.java

@@ -8,6 +8,7 @@ import org.springframework.test.context.ActiveProfiles;
 import org.springframework.test.web.servlet.MockMvc;
 
 import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
 
@@ -26,4 +27,12 @@ class GlobalExceptionHandlerTest {
                 .andExpect(jsonPath("$.code").value("VALIDATION_ERROR"))
                 .andExpect(jsonPath("$.traceId").isNotEmpty());
     }
+
+    @Test
+    void invalidRequestBodyReturnsChineseValidationMessage() throws Exception {
+        mvc.perform(post("/api/v1/auth/login").contentType("application/json").content("{}"))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.code").value("VALIDATION_ERROR"))
+                .andExpect(jsonPath("$.message").value("请求参数校验失败"));
+    }
 }