Mobile view overhaul: bottom nav, card inventory, camera scanner, PWA

Replace the cramped horizontal sidebar with a 5-tab bottom nav (Home,
Inventory, Scan, Custody, More) with an elevated scan button. Convert
the 10-column inventory table to card-based list on mobile with
scrollable filter pills and long-press selection. Add full-screen
camera barcode scanner using html5-qrcode with post-scan action sheet.
Set up PWA with vite-plugin-pwa for add-to-home-screen. Convert modals
to bottom sheets, add pull-to-refresh, safe-area padding, and iOS
input zoom fix.

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

web/package.json

@@ -11,6 +11,7 @@
   },
   "dependencies": {
     "@tanstack/react-query": "^5.62.7",
+    "html5-qrcode": "^2.3.8",
     "react": "^18.3.1",
     "react-dom": "^18.3.1",
     "react-router-dom": "^7.14.2"
@@ -20,6 +21,7 @@
     "@types/react-dom": "^18.3.5",
     "@vitejs/plugin-react": "^4.3.4",
     "typescript": "^5.7.2",
-    "vite": "^5.4.11"
+    "vite": "^5.4.11",
+    "vite-plugin-pwa": "^1.3.0"
   }
 }