Initial commit: Imperva WAF demo lab

Flight-booking app scaffolded from the source running on the GCP host,
plus the four-screen frontend and three OWASP attack endpoints (SQLi,
reflected XSS, path traversal) built and locally verified against a
live uvicorn/vite dev pair. Includes deploy.sh (local build -> ship
over ssh -> swap on host) and docs/ carried over from the handoff.

frontend/nginx.conf

@@ -0,0 +1,9 @@
+server {
+    listen 8080;
+    server_name localhost;
+    location / {
+        root /usr/share/nginx/html;
+        index index.html;
+        try_files $uri $uri/ /index.html;
+    }
+}