fix: 修复 VoiceController Map.of 兼容性 + ExploreController 参数不匹配

- VoiceController: Map.of() -> Collections.singletonMap() 兼容 Java 8
- ExploreController: 补齐 takeoutService.roll() 缺失的 taste/priceRange/allergies 参数

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

backend/src/main/java/com/chowbox/config/GlobalExceptionHandler.java

@@ -0,0 +1,17 @@
+package com.chowbox.config;
+
+import com.chowbox.model.ApiResponse;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+
+@Slf4j
+@RestControllerAdvice
+public class GlobalExceptionHandler {
+
+    @ExceptionHandler(Exception.class)
+    public ApiResponse<?> handleException(Exception e) {
+        log.error("Unhandled exception: {}", e.getMessage(), e);
+        return ApiResponse.fail(500, "服务器出了点小差，请稍后再试");
+    }
+}