feat(script-favorite): add ScriptFavoriteToggleRequest DTO

- Single field: scriptId with @NotBlank validation
- Uses javax.validation.constraints.NotBlank matching project convention

server/src/main/java/com/emotion/dto/request/ScriptFavoriteToggleRequest.java

@@ -0,0 +1,17 @@
+package com.emotion.dto.request;
+
+import lombok.Data;
+import javax.validation.constraints.NotBlank;
+
+/**
+ * 剧本收藏切换请求
+ *
+ * @author huazhongmin
+ * @date 2026-07-19
+ */
+@Data
+public class ScriptFavoriteToggleRequest {
+
+    @NotBlank(message = "剧本ID不能为空")
+    private String scriptId;
+}