Fix 18 UX issues: confirmations, undo, drawer nav, empty states, and polish

Comprehensive UX audit covering modals, drawers, dashboard, and inventory.
Key changes: confirmation steps before destructive actions, undo via toast
for consume/gone/checkout, back-navigation across entity drawers, optional
ratings, discrete item count field, audit progress bar, and sortable column
affordance.

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

web/src/types.ts

@@ -48,6 +48,7 @@ export interface InventoryItem {
   consumedDate: string | null;
   goneDate: string | null;
   checkoutDate: string | null;
+  prevBinId: string | null;
   rating: number | null;
   notes: string | null;
   audits: Audit[];