chore(deploy): add Dockerfile and nginx config for Coolify SPA hosting

Multi-stage build: node:22-alpine + pnpm builds, nginx:1.27-alpine
serves. VITE_* env vars are passed as build args because Vite inlines
them into the JS bundle at build time. nginx config does SPA fallback,
caches /assets/* immutably, and forces no-store on sw.js/index.html so
PWA updates propagate.

Dockerfile

@@ -0,0 +1,34 @@
+# syntax=docker/dockerfile:1.7
+
+# -------- Build stage --------
+FROM node:22-alpine AS builder
+WORKDIR /app
+
+# pnpm via corepack — pin the version that matches package.json
+RUN corepack enable && corepack prepare pnpm@11.5.0 --activate
+
+# Install deps first (cached as long as the lockfile is unchanged)
+COPY package.json pnpm-lock.yaml pnpm-workspace.yaml ./
+RUN pnpm install --frozen-lockfile
+
+# Build-time env (Vite inlines VITE_* into the bundle)
+ARG VITE_COUCHDB
+ARG VITE_MAPBOX_KEY
+ARG VITE_MAP_KEY
+ENV VITE_COUCHDB=$VITE_COUCHDB \
+    VITE_MAPBOX_KEY=$VITE_MAPBOX_KEY \
+    VITE_MAP_KEY=$VITE_MAP_KEY
+
+COPY . .
+RUN pnpm build
+
+# -------- Runtime stage --------
+FROM nginx:1.27-alpine
+
+COPY nginx.conf /etc/nginx/conf.d/default.conf
+COPY --from=builder /app/dist /usr/share/nginx/html
+
+EXPOSE 80
+
+HEALTHCHECK --interval=30s --timeout=3s --start-period=5s \
+  CMD wget -qO- http://127.0.0.1/ >/dev/null || exit 1