fix: nginx /kiwi/ alias for direct port access

Vite builds with VITE_BASE_URL=/kiwi so assets are referenced as
/kiwi/assets/... in index.html. When accessed via Caddy at the /kiwi
path, Caddy strips the prefix and nginx gets /assets/... correctly.
When accessed directly at localhost:8515, nginx had no /kiwi/ route
so the JS/CSS 404'd and the SPA never booted (blank page on hard refresh).

Add location ^~ /kiwi/ { alias ...; } — ^~ prevents the regex
\.(js|css|...)$ location from intercepting /kiwi/ paths first.

docker/web/nginx.cloud.conf

@@ -18,6 +18,15 @@ server {
         client_max_body_size 20m;
     }
 
+    # When accessed directly (localhost:8515) instead of via Caddy (/kiwi path-strip),
+    # Vite's /kiwi base URL means assets are requested at /kiwi/assets/... but stored
+    # at /assets/... in nginx's root. Alias /kiwi/ → root so direct port access works.
+    # ^~ prevents regex locations from overriding this prefix match for /kiwi/ paths.
+    location ^~ /kiwi/ {
+        alias /usr/share/nginx/html/;
+        try_files $uri $uri/ /index.html;
+    }
+
     location = /index.html {
         add_header Cache-Control "no-cache, no-store, must-revalidate";
         try_files $uri /index.html;