feat: filter meaningful conversations with local model

internal/extraction/processor_safety_test.go

@@ -12,6 +12,7 @@ type safetyTestGenerator struct{ calls int }
 func (g *safetyTestGenerator) Generate(context.Context, GenerationInput) (GenerationResult, error) {
 	g.calls++
 	return GenerationResult{
+		Meaningful: true, StoryWorthy: true, DecisionReason: "测试故事",
 		Summary: "模型摘要", OpenTopic: "开放话题", StoryTitle: "标题",
 		StoryContent: "模型输出风险", FactContent: "普通事实", AllowStory: true,
 	}, nil