UX overhaul: routing, accessibility, feedback, and polish

Add react-router-dom for URL-based navigation with browser
back/forward, deep links, and bookmarks. Replace window.confirm()
with styled ConfirmDialog. Add toast notifications and success
feedback on consume/audit/gone flows. Add escape-to-close and
focus trapping on modals. Add entrance animations for drawers,
modals, and toasts. Make grids responsive, add sortable inventory
headers, working CSV/JSON export, time-aware greeting, focus-visible
outlines, search clear button, and hover chevrons on inventory rows.

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

web/src/tokens.css

@@ -92,6 +92,11 @@ html, body {
 button { font-family: inherit; cursor: pointer; }
 input, select, textarea { font-family: inherit; }
 
+:focus-visible {
+  outline: 2px solid var(--sage);
+  outline-offset: 2px;
+}
+
 /* Subtle parchment texture */
 .parchment {
   background-image: