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>

.gitignore

@@ -18,3 +18,4 @@ web/dist
 
 # Claude Code local settings
 .claude/settings.local.json
+.gstack/