feat: add image management functionality

- Implemented image folder repository with CRUD operations.
- Added image reference repository for managing image references to articles.
- Created image repository for handling image assets, including listing, inserting, updating, and deleting images.
- Introduced image usage repository to track storage usage and quotas for tenants.
- Added SQL queries for image assets, folders, references, and usage.
- Developed image handler for HTTP endpoints to manage images and folders.
- Created database migration scripts for image-related tables and structures.

server/internal/tenant/repository/queries/image_reference.sql

@@ -0,0 +1,27 @@
+-- name: ListImageReferences :many
+SELECT r.id, r.tenant_id, r.image_asset_id, r.article_id, r.ref_scope, r.created_at
+FROM image_asset_references r
+WHERE r.tenant_id = sqlc.arg(tenant_id) AND r.image_asset_id = sqlc.arg(image_asset_id);
+
+-- name: CountImageReferences :one
+SELECT COUNT(*)::INT AS total
+FROM image_asset_references
+WHERE tenant_id = sqlc.arg(tenant_id) AND image_asset_id = sqlc.arg(image_asset_id);
+
+-- name: UpsertImageReference :exec
+INSERT INTO image_asset_references (tenant_id, image_asset_id, article_id, ref_scope)
+VALUES (sqlc.arg(tenant_id), sqlc.arg(image_asset_id), sqlc.arg(article_id), sqlc.arg(ref_scope))
+ON CONFLICT (image_asset_id, article_id, ref_scope) DO UPDATE SET updated_at = NOW();
+
+-- name: DeleteImageReferencesByArticle :exec
+DELETE FROM image_asset_references
+WHERE tenant_id = sqlc.arg(tenant_id) AND article_id = sqlc.arg(article_id);
+
+-- name: DeleteImageReferencesByArticleScope :exec
+DELETE FROM image_asset_references
+WHERE tenant_id = sqlc.arg(tenant_id) AND article_id = sqlc.arg(article_id) AND ref_scope = sqlc.arg(ref_scope);
+
+-- name: ListImageReferenceArticles :many
+SELECT DISTINCT r.article_id, r.ref_scope
+FROM image_asset_references r
+WHERE r.tenant_id = sqlc.arg(tenant_id) AND r.image_asset_id = sqlc.arg(image_asset_id);