refactor: update nginx config for new structure

- Updated posterg.conf with new directory structure
- Document root: /var/www/posterg/public
- Explicitly deny access to: /src, /templates, /config, /storage, /tests, /scripts, /docs
- Added structure diagram in comments
- Updated deploy scripts security checks
- Replaced outdated posterg.conf.reference

All non-public directories outside webroot for security.
Defense-in-depth: explicit deny rules even though paths outside /public.

nginx/deploy-production-new.sh

@@ -35,10 +35,10 @@ echo "✓ Set directory permissions to 755"
 find /var/www/posterg -type f -exec chmod 644 {} \;
 echo "✓ Set file permissions to 644"
 
-# Make database directory writable by group
-if [ -d "/var/www/posterg/database" ]; then
-    chmod 775 /var/www/posterg/database
-    echo "✓ Made database directory group-writable (775)"
+# Make storage directory writable by group
+if [ -d "/var/www/posterg/storage" ]; then
+    chmod 775 /var/www/posterg/storage
+    echo "✓ Made storage directory group-writable (775)"
 fi
 
 # Fix database file permissions