chore: relocate backend into apps/api ahead of monorepo merge

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/api/Dockerfile

@@ -0,0 +1,27 @@
+FROM pandoc/typst:latest-alpine AS typst
+
+FROM node:22-alpine
+
+# Enable corepack and activate pnpm
+RUN corepack enable && corepack prepare pnpm@11.3.0 --activate
+
+# pm2 manages the process; sequelize-cli runs migrations on startup
+RUN npm install -g pm2 sequelize-cli
+
+# Typst — compiles certificate.typ into the downloadable PDF certificate.
+# Not available as an apk package, so lift the binary out of pandoc/typst.
+COPY --from=typst /usr/bin/typst /usr/local/bin/typst
+
+WORKDIR /app
+
+# Install production dependencies only
+COPY package.json pnpm-lock.yaml pnpm-workspace.yaml ./
+RUN pnpm install --frozen-lockfile
+
+COPY . .
+
+RUN chmod +x docker-entrypoint.sh
+
+EXPOSE 3024
+
+ENTRYPOINT ["./docker-entrypoint.sh"]