Major projects submitted from different places share images

If two people with different databases submit major projects to the same s3 bucket, they get combined. Additionally, the way it works right now is it scans the s3 folder for images associated with the project, which is slow. Both of these problems could be solved by tracking images in the database so that displaying a project just displays the images that are actually associated with the major project.

先追蹤 major project 的提交與顯示流程，然後檢查現有的 S3 圖片掃描邏輯與資料庫模型。定義如何記錄每個專案的圖片關聯，並驗證來自不同資料庫或提交的專案不再混雜，同時顯示流程不再掃描 S3 資料夾。

由索引模型根據 Issue 內容生成。