feat(content_hash): propagate etag and hash_content to */resources

src/interfaces/api/handlers/folder_handler.rs

@@ -26,6 +26,7 @@ use crate::application::ports::folder_ports::FolderUseCase;
 use crate::application::ports::trash_ports::TrashUseCase;
 use crate::application::services::folder_service::FolderService;
 use crate::common::di::AppState as GlobalAppState;
+use crate::domain::entities::file::File;
 use crate::interfaces::errors::AppError;
 use crate::interfaces::middleware::auth::AuthUser;
 
@@ -717,14 +718,20 @@ pub async fn list_folder_resources(
                             .as_deref()
                             .unwrap_or("application/octet-stream");
                         let size_bytes = row.size.max(0) as u64;
-                        // `FolderResourceRow` (the UNION ALL row used
-                        // by this listing) doesn't carry `blob_hash`,
-                        // so neither `content_hash` nor `etag` can be
-                        // populated here without widening the SQL. The
-                        // REST file-listing UI doesn't issue
-                        // conditional requests against these rows —
-                        // file download / WebDAV PROPFIND go through
-                        // paths that DO carry the hash.
+                        // `blob_hash` is `Some(_)` for file rows in the
+                        // UNION ALL (`NULL` for folders). Route the
+                        // ETag formula through `File::compute_etag` —
+                        // the single source of truth shared with
+                        // GET/HEAD/PROPFIND/PUT response — so this
+                        // listing's `etag` byte-equals what a
+                        // conditional request would compare against.
+                        let modified_at_u = row.modified_at.timestamp() as u64;
+                        let content_hash = row.blob_hash.clone().unwrap_or_default();
+                        let etag = if content_hash.is_empty() {
+                            String::new()
+                        } else {
+                            File::compute_etag(&content_hash, modified_at_u)
+                        };
                         let dto = FileDto {
                             id: row.id.to_string(),
                             name: row.name.clone(),
@@ -740,8 +747,8 @@ pub async fn list_folder_resources(
                             size_formatted: format_file_size(size_bytes),
                             owner_id: Some(row.owner_id.to_string()),
                             sort_date: None,
-                            content_hash: String::new(),
-                            etag: String::new(),
+                            content_hash,
+                            etag,
                         };
                         FolderResourceItemDto {
                             resource_type: ResourceTypeDto::File,