refactor: implement worker pool pattern, add persistent task queue, and decouple target loading logic

internal/analyzer/deepseek.go

@@ -68,7 +68,7 @@ Job Content:
 	if err != nil {
 		return nil, fmt.Errorf("DeepSeek API call failed: %w", err)
 	}
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 
 	respBytes, err := io.ReadAll(resp.Body)
 	if err != nil {