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/package.json

@@ -12,7 +12,8 @@
   "dependencies": {
     "@tanstack/react-query": "^5.62.7",
     "react": "^18.3.1",
-    "react-dom": "^18.3.1"
+    "react-dom": "^18.3.1",
+    "react-router-dom": "^7.14.2"
   },
   "devDependencies": {
     "@types/react": "^18.3.17",