add K8s nginx config and parameterize Dockerfile.dashboard

Create nginx-k8s.conf that proxies to localhost:8000 instead of
api-gateway:8000 for K8s pods where both containers share a network
namespace. Update Dockerfile.dashboard to accept a NGINX_CONF build arg
(defaults to docker/nginx.conf for docker-compose compatibility).

docker/Dockerfile.dashboard

@@ -23,8 +23,9 @@ FROM nginx:alpine
 # Remove default nginx site
 RUN rm /etc/nginx/conf.d/default.conf
 
-# Copy custom nginx config
-COPY docker/nginx.conf /etc/nginx/conf.d/default.conf
+# Copy custom nginx config (override NGINX_CONF for K8s builds)
+ARG NGINX_CONF=docker/nginx.conf
+COPY ${NGINX_CONF} /etc/nginx/conf.d/default.conf
 
 # Copy built assets from the builder stage
 COPY --from=builder /app/dist /usr/share/nginx/html

docker/nginx-k8s.conf

@@ -0,0 +1,77 @@
+# nginx configuration for the trading-bot dashboard (Kubernetes variant).
+# Serves the React SPA and proxies API / WebSocket requests to the api-gateway.
+# In K8s both containers share a pod, so the upstream is localhost instead of
+# the Docker Compose service hostname "api-gateway".
+
+server {
+    listen 80;
+    server_name _;
+
+    root /usr/share/nginx/html;
+    index index.html;
+
+    # ---------------------------------------------------------------------------
+    # SPA: serve index.html for any path not matching a static file
+    # ---------------------------------------------------------------------------
+    location / {
+        try_files $uri $uri/ /index.html;
+    }
+
+    # ---------------------------------------------------------------------------
+    # Proxy /api/auth/* to the api-gateway /auth/* routes
+    # (Dashboard client uses baseURL=/api, so auth calls arrive as /api/auth/*)
+    # ---------------------------------------------------------------------------
+    location /api/auth/ {
+        proxy_pass http://localhost:8000/auth/;
+        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 /api/* to the api-gateway service
+    # ---------------------------------------------------------------------------
+    location /api/ {
+        proxy_pass http://localhost:8000/api/;
+        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 /auth/* to the api-gateway service
+    # ---------------------------------------------------------------------------
+    location /auth/ {
+        proxy_pass http://localhost:8000;
+        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 /health to the api-gateway service
+    # ---------------------------------------------------------------------------
+    location /health {
+        proxy_pass http://localhost:8000;
+        proxy_set_header Host $host;
+        proxy_set_header X-Real-IP $remote_addr;
+    }
+
+    # ---------------------------------------------------------------------------
+    # WebSocket upgrade for /ws
+    # ---------------------------------------------------------------------------
+    location /ws {
+        proxy_pass http://localhost:8000;
+        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_read_timeout 86400;
+    }
+}