feat(push): add GlobalExceptionHandler to expose actual error details

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

push-service/src/main/java/com/xuqm/push/controller/GlobalExceptionHandler.java

@@ -0,0 +1,28 @@
+package com.xuqm.push.controller;
+
+import com.xuqm.common.exception.BusinessException;
+import com.xuqm.common.model.ApiResponse;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+
+@RestControllerAdvice
+public class GlobalExceptionHandler {
+
+    private static final Logger log = LoggerFactory.getLogger(GlobalExceptionHandler.class);
+
+    @ExceptionHandler(BusinessException.class)
+    public ResponseEntity<ApiResponse<Void>> handleBusiness(BusinessException ex) {
+        return ResponseEntity.status(ex.getCode())
+                .body(ApiResponse.error(ex.getCode(), ex.getMessage()));
+    }
+
+    @ExceptionHandler(Exception.class)
+    public ResponseEntity<ApiResponse<Void>> handleUnexpected(Exception ex) {
+        log.error("Unexpected error", ex);
+        return ResponseEntity.status(500)
+                .body(ApiResponse.error(500, ex.getClass().getSimpleName() + ": " + ex.getMessage()));
+    }
+}