Serve PWA icons from fresh /icons/v2/ URLs with every iOS size

iOS showed a letter tile ('N') when adding to the Home Screen. The live files were fine, but a
reverse proxy in front of the app serves static files with a long cache lifetime (live icon.svg
and sw.js were stale) and iOS remembers a failed icon per URL.

- New versioned URLs no proxy/phone has cached; old paths kept for existing installs
- apple-touch-icon declared at 180/167/152/120 (opaque 8-bit RGB PNGs) for app and dashboard
- 180px icon also listed in both manifests; notification icons and root fallbacks use v2
- Service worker cache bumped

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

app/public/manifest.json

@@ -18,25 +18,31 @@
   ],
   "icons": [
     {
-      "src": "/icons/icon-192.png",
+      "src": "/icons/v2/icon-192.png",
       "sizes": "192x192",
       "type": "image/png",
       "purpose": "any"
     },
     {
-      "src": "/icons/icon-512.png",
+      "src": "/icons/v2/apple-touch-icon-180.png",
+      "sizes": "180x180",
+      "type": "image/png",
+      "purpose": "any"
+    },
+    {
+      "src": "/icons/v2/icon-512.png",
       "sizes": "512x512",
       "type": "image/png",
       "purpose": "any"
     },
     {
-      "src": "/icons/icon-maskable-512.png",
+      "src": "/icons/v2/icon-maskable-512.png",
       "sizes": "512x512",
       "type": "image/png",
       "purpose": "maskable"
     },
     {
-      "src": "/icons/icon.svg",
+      "src": "/icons/v2/icon.svg",
       "sizes": "any",
       "type": "image/svg+xml",
       "purpose": "any"
@@ -59,7 +65,7 @@
       "url": "/?tab=conditions",
       "icons": [
         {
-          "src": "/icons/icon-192.png",
+          "src": "/icons/v2/icon-192.png",
           "sizes": "192x192"
         }
       ]
@@ -71,7 +77,7 @@
       "url": "/?tab=station",
       "icons": [
         {
-          "src": "/icons/icon-192.png",
+          "src": "/icons/v2/icon-192.png",
           "sizes": "192x192"
         }
       ]
@@ -83,7 +89,7 @@
       "url": "/?tab=unified-map",
       "icons": [
         {
-          "src": "/icons/icon-192.png",
+          "src": "/icons/v2/icon-192.png",
           "sizes": "192x192"
         }
       ]
@@ -95,7 +101,7 @@
       "url": "/?tab=alerts",
       "icons": [
         {
-          "src": "/icons/icon-192.png",
+          "src": "/icons/v2/icon-192.png",
           "sizes": "192x192"
         }
       ]