Adiciona infra de deploy: Dockerfile multi-stage + nginx + .dockerignore

- Dockerfile: build com Node 20 (vite build) -> serve com nginx alpine
- nginx.conf: SPA routing, cache de assets versionados, healthcheck
- .dockerignore: exclui node_modules, dist e configs de IDE do contexto

Dockerfile

@@ -0,0 +1,24 @@
+# ============================
+# Stage 1 — Build (Vite + TypeScript)
+# ============================
+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 (nginx)
+# ============================
+FROM nginx:alpine
+
+COPY --from=builder /app/dist /usr/share/nginx/html
+COPY nginx.conf /etc/nginx/conf.d/default.conf
+
+EXPOSE 80
+
+CMD ["nginx", "-g", "daemon off;"]