Add bin types: reusable named dimension presets for bins

Bin types store a name, physical W×H in mm, and optional description.
When editing a bin, a type can be selected from a dropdown; this
pre-fills and locks the dimension inputs. Custom dimensions remain
available when no type is selected.

- lib/storage.mjs: bin type CRUD with bt: prefix
- server.mjs: /api/bin-types CRUD routes; type_id accepted on bin
  create/update routes; DELETE protected if any bin references the type;
  type dims copied onto bin when type_id is set
- public/lib/api.mjs: bin type wrappers; rename_bin → update_bin (accepts
  any fields)
- public/templates.html: Types tab in bins section; t-bin-type-row;
  t-dialog-bin-type; type selector in bin editor dialog
- public/app.mjs: all_bin_types state loaded at startup; render_bin_types_list();
  open_bin_type_dialog(); type selector in open_bin_editor(); /bins/types routing
- public/style.css: bin types list styles

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/storage.mjs

@@ -174,6 +174,28 @@ export function find_pdf_references(pdf_id) {
 	return list_components().filter(c => c.file_ids?.includes(pdf_id));
 }
 
+// --- Bin types ---
+
+export function list_bin_types() {
+	const result = [];
+	for (const [key] of store.data.entries()) {
+		if (key.startsWith('bt:')) result.push(store.get(key));
+	}
+	return result.sort((a, b) => a.name.localeCompare(b.name));
+}
+
+export function get_bin_type(id) {
+	return store.get(`bt:${id}`) ?? null;
+}
+
+export function set_bin_type(bt) {
+	store.set(`bt:${bt.id}`, bt);
+}
+
+export function delete_bin_type(id) {
+	return store.delete(`bt:${id}`);
+}
+
 // --- Bins ---
 
 export function list_bins() {