fix(ci): copy .npmrc before pnpm install in all Dockerfiles

The .npmrc file contains supportedArchitectures settings to force pnpm
to install glibc x64 binaries for native modules like matrix-sdk-crypto-nodejs.

Without copying this file into the Docker image, pnpm defaults to the
platform's native behavior which may skip or install incorrect binaries.

apps/api/Dockerfile

@@ -30,6 +30,9 @@ COPY packages/ui/package.json ./packages/ui/
 COPY packages/config/package.json ./packages/config/
 COPY apps/api/package.json ./apps/api/
 
+# Copy npm configuration for native binary architecture hints
+COPY .npmrc ./
+
 # Install dependencies (no cache mount — Kaniko builds are ephemeral in CI)
 # Then explicitly rebuild node-pty from source since pnpm may skip postinstall
 # scripts or fail to find prebuilt binaries for this Node.js version