feat(config): add log_conversations option to AI metadata configuration

internal/config/config.go

@@ -84,9 +84,10 @@ type AIEmbeddingConfig struct {
 }
 
 type AIMetadataConfig struct {
-	Model         string  `yaml:"model"`
-	FallbackModel string  `yaml:"fallback_model"`
-	Temperature   float64 `yaml:"temperature"`
+	Model            string  `yaml:"model"`
+	FallbackModel    string  `yaml:"fallback_model"`
+	Temperature      float64 `yaml:"temperature"`
+	LogConversations bool    `yaml:"log_conversations"`
 }
 
 type LiteLLMConfig struct {