Install with pnpm; npm deadlocks on the Spaces builder

Three builds died at exactly 8:00 in npm ci. Probes ruled out the obvious
causes: the registry answers in under a second, and tarballs pull at
163MB/s, so it is neither reachability nor throughput. npm itself hangs
there and the builder kills it at its limit; "Exit handler never called"
is what npm prints when SIGTERMed mid-install.

pnpm installs the same tree in 10s locally. Lockfile imported from
package-lock.json so versions are unchanged, then package-lock.json
removed to avoid two lockfiles drifting apart.

Dockerfile

@@ -1,26 +1,31 @@
 # syntax=docker/dockerfile:1
-# TEMPORARY diagnostic build — measures tarball throughput, then fails on
-# purpose so the logs surface. Restored to the real Dockerfile after.
-FROM node:22-slim
-RUN node -e "\
-const pull = async (u) => { \
-  const c = new AbortController(); \
-  const t = setTimeout(() => c.abort(), 60000); \
-  const t0 = Date.now(); \
-  try { \
-    const r = await fetch(u, {signal: c.signal}); \
-    const b = await r.arrayBuffer(); \
-    const s = (Date.now() - t0) / 1000; \
-    console.log((b.byteLength/1048576).toFixed(1)+'MB in '+s.toFixed(1)+'s = '+(b.byteLength/1048576/s).toFixed(2)+'MB/s', u.split('/').pop()); \
-  } catch (e) { console.log('FAIL', e.name, u.split('/').pop()); } \
-  finally { clearTimeout(t); } \
-}; \
-(async () => { \
-  const reg = 'https://registry.npmjs.org'; \
-  const meta = await (await fetch(reg+'/@next/swc-linux-x64-gnu')).json(); \
-  const v = meta.versions['16.3.4'] ? '16.3.4' : meta['dist-tags'].latest; \
-  await pull(meta.versions[v].dist.tarball); \
-  const ox = await (await fetch(reg+'/@tailwindcss/oxide-linux-x64-gnu')).json(); \
-  await pull(ox.versions[ox['dist-tags'].latest].dist.tarball); \
-  console.log('PROBE DONE'); process.exit(1); \
-})()"
+
+FROM node:22-slim AS deps
+WORKDIR /app
+RUN corepack enable
+COPY package.json pnpm-lock.yaml ./
+RUN pnpm install --frozen-lockfile
+
+FROM node:22-slim AS builder
+WORKDIR /app
+RUN corepack enable
+COPY --from=deps /app/node_modules ./node_modules
+COPY . .
+ENV NEXT_TELEMETRY_DISABLED=1
+RUN pnpm run build
+
+FROM node:22-slim AS runner
+WORKDIR /app
+ENV NODE_ENV=production
+ENV NEXT_TELEMETRY_DISABLED=1
+# Spaces routes traffic to 7860 and runs the container as uid 1000.
+ENV PORT=7860
+ENV HOSTNAME=0.0.0.0
+EXPOSE 7860
+
+COPY --from=builder /app/public ./public
+COPY --from=builder --chown=node:node /app/.next/standalone ./
+COPY --from=builder --chown=node:node /app/.next/static ./.next/static
+
+USER node
+CMD ["node", "server.js"]

package.json

@@ -27,5 +27,6 @@
     "eslint-config-next": "16.3.4",
     "tailwindcss": "^4",
     "typescript": "^5"
-  }
+  },
+  "packageManager": "pnpm@10.34.5"
 }