fix: use /tmp/nginx.pid to avoid permission denied errors (#877)

Set pid directive to /tmp/nginx.pid in nginx.conf and nginx.local.conf
to prevent permission denied errors when running nginx as a non-root user.

Co-authored-by: Claude <noreply@anthropic.com>

docker/nginx/nginx.conf

@@ -1,7 +1,7 @@
 events {
     worker_connections 1024;
 }
-
+pid /tmp/nginx.pid;
 http {
     # Basic settings
     sendfile on;

docker/nginx/nginx.local.conf

@@ -1,7 +1,7 @@
 events {
     worker_connections 1024;
 }
-
+pid /tmp/nginx.pid;
 http {
     # Basic settings
     sendfile on;