refactor: extract various constants

frontend/src/constants/documents.ts

@@ -0,0 +1,18 @@
+export const DEFAULT_THUMBNAIL_SIZE = 48;
+
+export const TAG_MIME_TYPES = ['application/x-papercrate-tag', 'text/papercrate-tag'] as const;
+export const TAG_TEXT_MIME_TYPE = 'text/plain';
+
+export const DEFAULT_GRID_ICON_SIZE = 144;
+
+export const SORT_OPTIONS = [
+  { value: 'title', label: 'Title' },
+  { value: 'issued_at', label: 'Issued date' },
+  { value: 'created_at', label: 'Added' },
+  { value: 'updated_at', label: 'Updated date' },
+] as const;
+
+export const SORT_LABEL_LOOKUP = SORT_OPTIONS.reduce<Record<string, string>>((acc, option) => {
+  acc[option.value] = option.label;
+  return acc;
+}, {});