fix: Remove duplicate daemon directive in nginx config

Use standard nginx.conf and only override the site config in sites-available.
This prevents the 'daemon' directive duplicate error.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

user-template-vcoder/Dockerfile

@@ -59,27 +59,22 @@ RUN rm -f /tmp/cpptools.vsix /tmp/platformio.vsix
 RUN apt-get update && apt-get install -y socat nginx && rm -rf /var/lib/apt/lists/*
 
 # nginx als Reverse Proxy für code-server (fixiert Subpath-Routing)
-RUN printf 'daemon off;\n\
-pid /tmp/nginx.pid;\n\
-events { worker_connections 1024; }\n\
-http {\n\
+RUN mkdir -p /etc/nginx/sites-available && printf 'server {\n\
+    listen 8080;\n\
+    server_name localhost;\n\
     access_log /tmp/nginx-access.log;\n\
     error_log /tmp/nginx-error.log;\n\
-    server {\n\
-        listen 8080;\n\
-        server_name localhost;\n\
-        location / {\n\
-            proxy_pass http://127.0.0.1:8081;\n\
-            proxy_http_version 1.1;\n\
-            proxy_set_header Upgrade $http_upgrade;\n\
-            proxy_set_header Connection "upgrade";\n\
-            proxy_set_header Host $host;\n\
-            proxy_set_header X-Real-IP $remote_addr;\n\
-            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;\n\
-            proxy_set_header X-Forwarded-Proto $scheme;\n\
-        }\n\
+    location / {\n\
+        proxy_pass http://127.0.0.1:8081;\n\
+        proxy_http_version 1.1;\n\
+        proxy_set_header Upgrade $http_upgrade;\n\
+        proxy_set_header Connection "upgrade";\n\
+        proxy_set_header Host $host;\n\
+        proxy_set_header X-Real-IP $remote_addr;\n\
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;\n\
+        proxy_set_header X-Forwarded-Proto $scheme;\n\
     }\n\
-}\n' > /etc/nginx/nginx.conf
+}\n' > /etc/nginx/sites-available/default && ln -sf /etc/nginx/sites-available/default /etc/nginx/sites-enabled/default
 
 # Entrypoint-Script - startet nginx + socat + code-server
 RUN printf '#!/bin/bash\n\