# Resource Library Design

**Goal:** Build a real resource-library backend for models, scenes, and garments with S3 direct-upload preparation, persisted resource metadata, and list APIs that the existing frontend library pages can consume.

**Scope:** Replace mock resource-library data with a dedicated backend resource domain. The first slice supports public-read assets, presigned upload preparation, one-shot resource creation, and real list retrieval. Upload UI is out of scope; API tests and existing frontend readers are the verification path.

**Decisions**

- Resource-library records are independent from order-generated assets.
- Files are stored in S3 and read publicly through the configured CDN hostname.
- Uploads use a two-step direct-upload flow:
  1. Backend issues presigned upload parameters and storage metadata.
  2. Client uploads to S3 and then creates the resource record with uploaded file metadata.
- A resource can include:
  - one original file
  - one thumbnail file
  - multiple gallery files
- Type-specific fields in the first version:
  - model: `gender`, `age_group`
  - scene: `environment`
  - garment: `category`
- Garment category remains a plain string for now. Config management can come later.

**Backend Shape**

- Add a dedicated `library_resources` table for business metadata.
- Add a dedicated `library_resource_files` table for uploaded file references.
- Add enums for resource type, file role, and optional status/environment metadata.
- Add API routes for:
  - upload presign
  - resource create
  - resource list
- Keep the existing order asset model untouched.

**Frontend Shape**

- Keep the existing frontend library pages and submit-workbench readers.
- Replace the current mock BFF implementation with a proxy that calls the new backend list endpoint and maps backend payloads into the existing `LibraryItemVM`.
- Upload UI is deferred. No new client-side upload forms are required in this slice.

**Verification**

- Backend integration tests cover:
  - presign response generation
  - resource creation with original/thumbnail/gallery files
  - filtered resource listing by type and type-specific fields
- Frontend route tests cover:
  - successful proxying and mapping from backend payload to existing view-model shape
  - unsupported library-type rejection remains normalized