Fix blackroad.systems domain configuration and Nginx setup

## Problem
The blackroad.systems domain was returning HTTP 403 Forbidden with a
fallback page ("Status: Nginx API") instead of serving the BlackRoad OS
application. This was caused by:

1. Domain configured in "forward" mode instead of DNS mode
2. Missing or misconfigured Nginx server blocks
3. Requests falling through to default server block

## Solution

### 1. Updated Domain Configuration (ops/domains.yaml)
- Changed blackroad.systems from "forward" to "dns" mode
- Domain now points directly to application server via CNAME
- Established blackroad.systems as canonical apex domain
- www.blackroad.systems redirects to apex domain (301)
- Aligns with DOMAIN_SPEC.md positioning as flagship corporate site

### 2. Created Nginx Configuration (ops/nginx/blackroad.systems.conf)
- Proper server_name directives for blackroad.systems
- HTTP to HTTPS redirects (301)
- www to apex domain redirects (301)
- Modern SSL/TLS configuration
- Security headers (HSTS, X-Frame-Options, etc.)
- SPA fallback routing with try_files
- Static asset caching with versioning
- Health check endpoint at /healthz
- Separate server blocks for apex and www subdomains

### 3. Deployment Guide (ops/DOMAIN_FIX_GUIDE.md)
- Step-by-step deployment instructions
- DNS configuration and verification
- SSL certificate setup
- Nginx deployment and testing
- Troubleshooting guide
- Post-deployment validation checklist

## Testing Required

After deployment:
1. Apply DNS changes: python3 ops/scripts/apply_domains.py
2. Deploy Nginx config to server
3. Obtain SSL certificates
4. Verify all redirects and endpoints
5. Purge CDN caches if applicable

## References
- blackroad-universe/domains/blackroad-systems/DOMAIN_SPEC.md
- ops/scripts/apply_domains.py

ops/nginx/blackroad.systems.conf

@@ -0,0 +1,166 @@
+# Nginx server block configuration for blackroad.systems
+# This configuration ensures the domain serves the BlackRoad OS application
+# instead of falling back to a default server block
+
+# Redirect HTTP to HTTPS for apex domain
+server {
+    listen 80;
+    listen [::]:80;
+    server_name blackroad.systems;
+
+    # Redirect all HTTP requests to HTTPS
+    return 301 https://blackroad.systems$request_uri;
+}
+
+# Redirect HTTP to HTTPS for www subdomain
+server {
+    listen 80;
+    listen [::]:80;
+    server_name www.blackroad.systems;
+
+    # Redirect www to apex domain over HTTPS
+    return 301 https://blackroad.systems$request_uri;
+}
+
+# Redirect HTTPS www to apex domain
+server {
+    listen 443 ssl http2;
+    listen [::]:443 ssl http2;
+    server_name www.blackroad.systems;
+
+    # SSL certificate configuration
+    ssl_certificate /etc/ssl/certs/blackroad_systems.fullchain.pem;
+    ssl_certificate_key /etc/ssl/private/blackroad_systems.key;
+
+    # Modern SSL configuration
+    ssl_protocols TLSv1.2 TLSv1.3;
+    ssl_ciphers HIGH:!aNULL:!MD5;
+    ssl_prefer_server_ciphers on;
+
+    # Redirect www to apex domain
+    return 301 https://blackroad.systems$request_uri;
+}
+
+# Main HTTPS server block for blackroad.systems
+server {
+    listen 443 ssl http2;
+    listen [::]:443 ssl http2;
+    server_name blackroad.systems;
+
+    # SSL certificate configuration
+    ssl_certificate /etc/ssl/certs/blackroad_systems.fullchain.pem;
+    ssl_certificate_key /etc/ssl/private/blackroad_systems.key;
+
+    # Modern SSL configuration
+    ssl_protocols TLSv1.2 TLSv1.3;
+    ssl_ciphers HIGH:!aNULL:!MD5;
+    ssl_prefer_server_ciphers on;
+    ssl_session_cache shared:SSL:10m;
+    ssl_session_timeout 10m;
+
+    # Security headers
+    add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
+    add_header X-Frame-Options "SAMEORIGIN" always;
+    add_header X-Content-Type-Options "nosniff" always;
+    add_header X-XSS-Protection "1; mode=block" always;
+
+    # Document root - point to your BlackRoad OS build
+    # Adjust this path to match your actual deployment location
+    root /var/www/blackroad/current;
+    index index.html index.htm;
+
+    # Health check endpoint (separate from main route)
+    location = /healthz {
+        access_log off;
+        return 200 "ok\n";
+        add_header Content-Type text/plain;
+    }
+
+    # API proxy (if you have a backend API)
+    # Uncomment and adjust if needed
+    # location /api/ {
+    #     proxy_pass http://localhost:3000/;
+    #     proxy_http_version 1.1;
+    #     proxy_set_header Upgrade $http_upgrade;
+    #     proxy_set_header Connection 'upgrade';
+    #     proxy_set_header Host $host;
+    #     proxy_set_header X-Real-IP $remote_addr;
+    #     proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+    #     proxy_set_header X-Forwarded-Proto $scheme;
+    #     proxy_cache_bypass $http_upgrade;
+    # }
+
+    # Static assets with long cache
+    location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff|woff2|ttf|eot)$ {
+        expires 1y;
+        add_header Cache-Control "public, immutable";
+        access_log off;
+    }
+
+    # SPA fallback - serve index.html for all routes
+    # This ensures client-side routing works correctly
+    location / {
+        try_files $uri $uri/ /index.html;
+
+        # Cache control for HTML
+        add_header Cache-Control "no-store, no-cache, must-revalidate, proxy-revalidate, max-age=0";
+    }
+
+    # Deny access to hidden files
+    location ~ /\. {
+        deny all;
+        access_log off;
+        log_not_found off;
+    }
+
+    # Custom error pages
+    error_page 404 /404.html;
+    error_page 500 502 503 504 /50x.html;
+    location = /50x.html {
+        root /var/www/blackroad/current;
+    }
+}
+
+# Optional: Server block for os.blackroad.systems
+# If you want os.blackroad.systems to also serve the application
+server {
+    listen 443 ssl http2;
+    listen [::]:443 ssl http2;
+    server_name os.blackroad.systems;
+
+    # SSL certificate configuration
+    ssl_certificate /etc/ssl/certs/blackroad_systems.fullchain.pem;
+    ssl_certificate_key /etc/ssl/private/blackroad_systems.key;
+
+    # Modern SSL configuration
+    ssl_protocols TLSv1.2 TLSv1.3;
+    ssl_ciphers HIGH:!aNULL:!MD5;
+    ssl_prefer_server_ciphers on;
+
+    # Same configuration as main domain
+    root /var/www/blackroad/current;
+    index index.html index.htm;
+
+    location = /healthz {
+        access_log off;
+        return 200 "ok\n";
+        add_header Content-Type text/plain;
+    }
+
+    location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff|woff2|ttf|eot)$ {
+        expires 1y;
+        add_header Cache-Control "public, immutable";
+        access_log off;
+    }
+
+    location / {
+        try_files $uri $uri/ /index.html;
+        add_header Cache-Control "no-store, no-cache, must-revalidate, proxy-revalidate, max-age=0";
+    }
+
+    location ~ /\. {
+        deny all;
+        access_log off;
+        log_not_found off;
+    }
+}