Initial scaffold: unified customer/insurance/utilities platform

Next.js + NestJS + Prisma (MySQL) monorepo replacing the legacy PHP
internal app. Includes a session-based auth module with Argon2 password
hashing and global input validation (replacing the old app's SQL
injection and plaintext password comparison), the full target Prisma
schema for customers/insurance/utilities/shared ledger/bank register,
Docker Compose + Dockerfiles, and an Access-to-staging migration
pipeline (migration/) already run against the real source databases.

See PLAN.md and RESUME.md for the full architecture and session history.

docker/web.Dockerfile

@@ -0,0 +1,20 @@
+FROM node:20-alpine AS base
+WORKDIR /repo
+
+FROM base AS deps
+COPY package.json package-lock.json* ./
+COPY apps/web/package.json apps/web/package.json
+RUN npm install --workspace=apps/web --no-audit --no-fund
+
+FROM deps AS build
+COPY apps/web apps/web
+RUN npm run build -w apps/web
+
+FROM node:20-alpine AS runtime
+WORKDIR /repo
+ENV NODE_ENV=production
+COPY --from=build /repo/node_modules node_modules
+COPY --from=build /repo/apps/web apps/web
+EXPOSE 3000
+WORKDIR /repo/apps/web
+CMD ["npx", "next", "start"]