fix: overhaul PWA icons with v2 suffix to bust all cache layers

- Redesign favicon SVG with gradient border matching splash screen
- Rename all icon files with -v2 suffix to bypass browser/SW/PWA caches
- Delete 9 old/duplicate icon files (~13MB removed)
- Add nginx cache-control headers for icons and manifest
- Rename assets-cache to assets-cache-v2 to orphan stale SW cache
- Update all HTML, manifest, and component icon references

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

image-recipe/configs/nginx-archipelago.conf

@@ -10,7 +10,7 @@ server {
     location /aiui/ {
         alias /opt/archipelago/web-ui/aiui/;
         index index.html;
-        try_files $uri $uri/ =404;
+        try_files $uri $uri/ /aiui/index.html;
     }
 
     # AIUI Claude API proxy — routes through claude-proxy service (port 3141)
@@ -54,6 +54,12 @@ server {
         return 503 '{"error":"SearXNG is not running"}';
     }
 
+    # Icons, favicon, manifest — always revalidate (no heuristic caching)
+    location ~* ^/(favicon\.ico|manifest\.webmanifest|assets/icon/) {
+        add_header Cache-Control "no-cache, must-revalidate";
+        try_files $uri =404;
+    }
+
     # Serve static files (Vue.js SPA)
     location / {
         try_files $uri $uri/ /index.html;
@@ -385,17 +391,23 @@ server {
         proxy_send_timeout 120s;
     }
 
+    # Icons, favicon, manifest — always revalidate (no heuristic caching)
+    location ~* ^/(favicon\.ico|manifest\.webmanifest|assets/icon/) {
+        add_header Cache-Control "no-cache, must-revalidate";
+        try_files $uri =404;
+    }
+
     location / {
         try_files $uri $uri/ /index.html;
     }
-    
+
     location /archipelago/ {
         proxy_pass http://127.0.0.1:5678;
         proxy_http_version 1.1;
         proxy_set_header Host $host;
         proxy_set_header X-Real-IP $remote_addr;
     }
-    
+
     location /rpc/ {
         proxy_pass http://127.0.0.1:5678;
         proxy_http_version 1.1;
@@ -405,7 +417,7 @@ server {
         proxy_send_timeout 600s;
         proxy_read_timeout 600s;
     }
-    
+
     location /app/nextcloud/ {
         proxy_pass http://127.0.0.1:8085/;
         proxy_http_version 1.1;