Add Docker, NGINX config, and CI workflow

Introduces Dockerfile and nginx.conf for containerized deployment of the Angular frontend. Adds a GitHub Actions workflow for automated Docker image build and push. Updates README with setup, tech stack, and deployment instructions.

nginx.conf

@@ -0,0 +1,10 @@
+server {
+  listen 80;
+  server_name _;
+  root /usr/share/nginx/html;
+  index index.html;
+
+  location / {
+    try_files $uri $uri/ /index.html;
+  }
+}