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/RedisConfig.java

@@ -0,0 +1,21 @@
+package com.chowbox.config;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.data.redis.connection.RedisConnectionFactory;
+import org.springframework.data.redis.core.RedisTemplate;
+import org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer;
+import org.springframework.data.redis.serializer.StringRedisSerializer;
+
+@Configuration
+public class RedisConfig {
+
+    @Bean
+    public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) {
+        RedisTemplate<String, Object> template = new RedisTemplate<>();
+        template.setConnectionFactory(factory);
+        template.setKeySerializer(new StringRedisSerializer());
+        template.setValueSerializer(new GenericJackson2JsonRedisSerializer());
+        return template;
+    }
+}