fix: update pnpm configuration to set store directory for Docker volume

.devcontainer/app/postCreateCommand.sh

@@ -21,6 +21,10 @@ curl -fsSL https://claude.ai/install.sh | bash
 export PNPM_HOME="${PNPM_HOME:-$HOME/.local/share/pnpm}"
 export PATH="$PNPM_HOME/bin:$HOME/.local/bin:$PATH"
 mkdir -p "$PNPM_HOME"
+# Use the Docker volume mounted at /workspace/.pnpm-store (see .devcontainer/compose.yml).
+# Without this, pnpm auto-falls-back to <workspace>/.pnpm-store because $HOME
+# (overlay FS) and the workspace (bind mount) are on different filesystems.
+pnpm config set store-dir /workspace/.pnpm-store
 
 pnpm install --global turbo typescript-language-server typescript