Add project scaffolding and infrastructure config

pnpm monorepo with shared packages, server, and UI workspaces.
Includes Docker multi-stage build, Postgres compose, and root TypeScript/Vitest config.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Dockerfile

@@ -0,0 +1,38 @@
+FROM node:20-alpine AS base
+RUN corepack enable
+
+FROM base AS deps
+WORKDIR /app
+COPY package.json pnpm-workspace.yaml pnpm-lock.yaml .npmrc ./
+COPY packages/shared/package.json packages/shared/
+COPY packages/db/package.json packages/db/
+COPY server/package.json server/
+COPY ui/package.json ui/
+RUN pnpm install --frozen-lockfile
+
+FROM base AS build
+WORKDIR /app
+COPY --from=deps /app/node_modules node_modules
+COPY --from=deps /app/packages/shared/node_modules packages/shared/node_modules
+COPY --from=deps /app/packages/db/node_modules packages/db/node_modules
+COPY --from=deps /app/server/node_modules server/node_modules
+COPY --from=deps /app/ui/node_modules ui/node_modules
+COPY . .
+RUN pnpm --filter @paperclip/ui build
+RUN pnpm --filter @paperclip/server build
+
+FROM base AS production
+WORKDIR /app
+COPY --from=deps /app/node_modules node_modules
+COPY --from=deps /app/packages/shared/node_modules packages/shared/node_modules
+COPY --from=deps /app/packages/db/node_modules packages/db/node_modules
+COPY --from=deps /app/server/node_modules server/node_modules
+COPY --from=build /app/packages/shared packages/shared
+COPY --from=build /app/packages/db packages/db
+COPY --from=build /app/server/dist server/dist
+COPY --from=build /app/server/package.json server/package.json
+COPY --from=build /app/ui/dist ui/dist
+COPY package.json pnpm-workspace.yaml ./
+
+EXPOSE 3100
+CMD ["node", "server/dist/index.js"]