feat: add E2E tests with mock Nginx services, update Traefik routing to use service names, and integrate testing into the CI workflow.

tests/mock_nginx/nginx.conf

@@ -0,0 +1,26 @@
+events {}
+
+http {
+    server {
+        listen 80;
+        server_name _;
+
+        location / {
+            add_header X-Mock-Service "true";
+            return 200 "Mock Nginx HTTP\n";
+        }
+    }
+
+    server {
+        listen 443 ssl;
+        server_name _;
+
+        ssl_certificate /etc/nginx/certs/server.crt;
+        ssl_certificate_key /etc/nginx/certs/server.key;
+
+        location / {
+            add_header X-Mock-Service "true";
+            return 200 "Mock Nginx HTTPS\n";
+        }
+    }
+}