feat: frontend-ready backend — pagination, auto-derivatives, list endpoints, bulk ops, OpenAPI

Pagination: count_by_owner + count_search on AssetRepository,
timeline/search return real total count (not page len).

Auto-derivatives: worker enqueues GenerateDerivative when
ExtractMetadata job completes, closing the upload→thumbnail gap.

List endpoints: GET /albums, GET /stacks with user scoping.
ListAlbumsHandler, ListStacksHandler, find_by_owner on AssetStackRepository.

Tag filtering: tag_name field on AssetFilters, JOIN asset_tags+tags
in postgres search/count queries.

Bulk operations: POST /assets/bulk-delete, POST /assets/bulk-tag.

Album update: PUT /albums/{id} with UpdateAlbumHandler (title, description).

OpenAPI: utoipa annotations on all 47 endpoints + all request/response
schemas registered. Scalar UI at /scalar covers full API.

crates/presentation/src/routes.rs

@@ -26,8 +26,14 @@ fn protected_routes(state: &AppState) -> Router<AppState> {
         .route("/auth/me", get(auth::me))
         .route("/auth/logout", post(auth::logout))
         // albums
-        .route("/albums", post(albums::create_album))
-        .route("/albums/{id}", get(albums::get_album))
+        .route(
+            "/albums",
+            get(albums::list_albums).post(albums::create_album),
+        )
+        .route(
+            "/albums/{id}",
+            get(albums::get_album).put(albums::update_album),
+        )
         .route("/albums/{id}/entries", post(albums::add_entry))
         .route(
             "/albums/{id}/entries/{asset_id}",
@@ -49,8 +55,13 @@ fn protected_routes(state: &AppState) -> Router<AppState> {
             get(assets::serve_derivative),
         )
         .route("/assets/{id}/tags", post(assets::tag_asset))
+        .route("/assets/bulk-delete", post(assets::bulk_delete))
+        .route("/assets/bulk-tag", post(assets::bulk_tag))
         // stacks
-        .route("/stacks", post(stacks::create_stack))
+        .route(
+            "/stacks",
+            get(stacks::list_stacks).post(stacks::create_stack),
+        )
         .route(
             "/stacks/detect-live-photos",
             post(stacks::detect_live_photos),