Dockerize backend, frontend, and database into separate containers

- backend/Dockerfile: multi-stage Python build (builder + slim runtime)
- frontend/Dockerfile: multi-stage Node build + nginx:alpine serving
- frontend/nginx.conf: SPA routing + /api/ reverse proxy to backend
- docker-compose.yml: production compose with health checks and proper dependency ordering
- docker-compose.dev.yml: dev overrides with hot reload via volume mounts

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/Dockerfile

@@ -0,0 +1,18 @@
+# ── Stage 1: build ────────────────────────────────────────────────────────────
+FROM node:20-alpine AS builder
+
+WORKDIR /app
+
+COPY package.json package-lock.json* ./
+RUN npm ci
+
+COPY . .
+RUN npm run build
+
+# ── Stage 2: serve with nginx ─────────────────────────────────────────────────
+FROM nginx:alpine
+
+COPY --from=builder /app/dist /usr/share/nginx/html
+COPY nginx.conf /etc/nginx/conf.d/default.conf
+
+EXPOSE 80

frontend/nginx.conf

@@ -0,0 +1,17 @@
+server {
+    listen 80;
+    root /usr/share/nginx/html;
+    index index.html;
+
+    # Proxy API calls to the backend container
+    location /api/ {
+        proxy_pass http://backend:8000;
+        proxy_set_header Host $host;
+        proxy_set_header X-Real-IP $remote_addr;
+    }
+
+    # SPA fallback — all non-asset routes serve index.html
+    location / {
+        try_files $uri $uri/ /index.html;
+    }
+}