feat: add Docker support with demo mode and database reset functionality

Dockerfile

@@ -0,0 +1,24 @@
+# SPDX-FileCopyrightText: 2026 Paul Schoeneck
+#
+# SPDX-License-Identifier: AGPL-3.0-only AND LicenseRef-KIBU-Additional-Terms
+
+FROM node:22-bookworm-slim AS build
+WORKDIR /app
+ENV NEXT_TELEMETRY_DISABLED=1
+COPY package.json package-lock.json ./
+RUN npm ci
+COPY . .
+RUN sed -i 's/\r$//' scripts/docker-entrypoint.sh && npm run build
+
+FROM node:22-bookworm-slim AS runtime
+WORKDIR /app
+ENV NODE_ENV=production NEXT_TELEMETRY_DISABLED=1 PORT=3000
+LABEL org.opencontainers.image.title="KIBU" \
+      org.opencontainers.image.source="https://git.voidcube.de/pixo2000/KIBU" \
+      org.opencontainers.image.licenses="AGPL-3.0-only AND LicenseRef-KIBU-Additional-Terms"
+COPY --from=build --chown=node:node /app /app
+USER node
+EXPOSE 3000
+HEALTHCHECK --interval=10s --timeout=5s --start-period=60s --retries=6 \
+  CMD node -e "fetch('http://127.0.0.1:'+process.env.PORT+'/login').then(r=>{if(!r.ok)process.exit(1)}).catch(()=>process.exit(1))"
+ENTRYPOINT ["sh", "scripts/docker-entrypoint.sh"]