Add Compose stack & Caddy deploy artifacts (task 05)

Multi-stage Dockerfile (pnpm fetch/offline, standalone output, non-root
nextjs user), deploy/compose.yaml with famapp + famapp-db + full Authentik
stack on famapp_net, Caddyfile.snippet for fam/auth.ginnoir.com, and
.env.production.example. Added .dockerignore and public/.gitkeep.

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

Dockerfile

@@ -0,0 +1,37 @@
+# syntax=docker/dockerfile:1
+
+# ── Stage 1: fetch dependencies ───────────────────────────────────────────────
+FROM node:22-alpine AS deps
+RUN corepack enable && corepack prepare pnpm@10.33.3 --activate
+WORKDIR /app
+COPY package.json pnpm-lock.yaml .npmrc ./
+# Populate the pnpm virtual store; this layer is cached until lock file changes.
+RUN pnpm fetch
+
+# ── Stage 2: build ────────────────────────────────────────────────────────────
+FROM deps AS builder
+WORKDIR /app
+# CI=true prevents pnpm from prompting for TTY confirmation when removing modules dir
+ENV CI=true
+ENV NEXT_TELEMETRY_DISABLED=1
+COPY . .
+RUN pnpm install --offline --frozen-lockfile
+RUN pnpm build
+
+# ── Stage 3: production runtime ───────────────────────────────────────────────
+FROM node:22-alpine AS runner
+WORKDIR /app
+ENV NODE_ENV=production
+ENV PORT=3000
+ENV HOSTNAME=0.0.0.0
+
+RUN addgroup --system --gid 1001 nodejs \
+ && adduser --system --uid 1001 nextjs
+
+COPY --from=builder --chown=nextjs:nodejs /app/.next/standalone ./
+COPY --from=builder --chown=nextjs:nodejs /app/.next/static ./.next/static
+COPY --from=builder --chown=nextjs:nodejs /app/public ./public
+
+USER nextjs
+EXPOSE 3000
+CMD ["node", "server.js"]