infra: docker compose dev + production Dockerfiles

- docker-compose.dev.yml: hot-reload dev stack (rete-watch + server :7357 + web :5173)
- docker-compose.yml: production stack
- packages/chess/Dockerfile + nginx.conf: chess web image
- packages/server/Dockerfile: server image
- Dockerfile.dev: shared dev base image (Bun + workspace deps preinstalled)
- .dockerignore: build context exclusions

Used by Playwright e2e tests (run via .sisyphus/scripts/run-pw.sh which connects to the running dev stack instead of spawning its own server).

packages/chess/nginx.conf

@@ -0,0 +1,18 @@
+server {
+    listen 80;
+    server_name _;
+    root /usr/share/nginx/html;
+    index index.html;
+
+    # SPA history fallback — react-router uses client-side routes.
+    location / {
+        try_files $uri $uri/ /index.html;
+    }
+
+    # Cache hashed Vite assets aggressively.
+    location /assets/ {
+        access_log off;
+        add_header Cache-Control "public, max-age=31536000, immutable";
+        try_files $uri =404;
+    }
+}