chore(docker): add containerized deployment and nginx proxy

docker/frontend.Dockerfile

@@ -0,0 +1,29 @@
+# syntax=docker/dockerfile:1.7
+FROM node:20-alpine AS base
+ENV PNPM_HOME=/pnpm
+ENV PATH=$PNPM_HOME:$PATH
+RUN corepack enable && corepack prepare pnpm@9.12.0 --activate
+
+# ---------- deps ----------
+FROM base AS deps
+WORKDIR /app
+COPY package.json pnpm-workspace.yaml pnpm-lock.yaml* ./
+COPY tsconfig.base.json ./
+COPY packages/shared/package.json packages/shared/
+COPY apps/backend/package.json apps/backend/
+COPY apps/frontend/package.json apps/frontend/
+RUN pnpm install --filter @family-wishlist/frontend... --frozen-lockfile || \
+    pnpm install --filter @family-wishlist/frontend...
+
+# ---------- build ----------
+FROM deps AS build
+WORKDIR /app
+COPY packages/shared packages/shared
+COPY apps/frontend apps/frontend
+RUN pnpm --filter @family-wishlist/frontend build
+
+# ---------- runtime (nginx) ----------
+FROM nginx:1.27-alpine AS runtime
+COPY docker/nginx.conf /etc/nginx/conf.d/default.conf
+COPY --from=build /app/apps/frontend/dist /usr/share/nginx/html
+EXPOSE 80