build: Use pnpm's default package import method (no-changelog) (#39019)

Co-authored-by: Claude Fable 5.1 <[email protected]>

.devcontainer/codespaces/Dockerfile

@@ -37,4 +37,7 @@ ENV PNPM_HOME=/home/node/.local/share/pnpm
 ENV PATH=$PNPM_HOME/bin:$PATH
 
 USER node
-RUN mkdir -p $PNPM_HOME ~/.pnpm-store && pnpm config set store-dir ~/.pnpm-store --global
+# The store must sit on the same filesystem as the worktrees (/workspaces is its own
+# mount), or pnpm copies node_modules into every worktree instead of hardlinking.
+# The directory is created on the first install: Codespaces mounts /workspaces at runtime.
+RUN mkdir -p $PNPM_HOME && pnpm config set store-dir /workspaces/.pnpm-store --global

.devcontainer/codespaces/README.md

@@ -46,7 +46,8 @@ create an 8-core Codespace by default.
   `session/<name>`), so parallel agents never touch each other's tree. Builds
   in fresh worktrees are cache-hits via a shared turbo cache.
 - First codespace creation takes ~20 min uncached (image + full build). After
-  that, sessions attach instantly; new worktrees cost a `pnpm install` (~1–2 min).
+  that, sessions attach instantly; new worktrees cost a `pnpm install` (~10 s: the
+  store lives on `/workspaces`, so `node_modules` is hardlinked, not copied).
 
 ## Configure the local OpenCode harness
 

pnpm-workspace.yaml

@@ -20,7 +20,6 @@ verifyDepsBeforeRun: false
 pmOnFail: warn
 updateNotifier: false
 loglevel: warn
-packageImportMethod: clone-or-copy
 
 minimumReleaseAge: 2880
 # Blacksmith's path to Cloudflare AMS intermittently stalls a single connection