fix(devcontainer): Fix pnpm installation issue in postinstall.sh (#4886)

## Description

1. What is this PR about (link the issue and add a short description)
* This PR fixes an issue where `pnpm` was not being correctly installed
or configured within the Devcontainer environment when using
`postinstall.sh`.
* This was causing errors during container startup and when running
`pnpm` commands inside the Devcontainer.
* The fix ensures `pnpm` is properly set up in `postinstall.sh`,
resolving the Devcontainer setup issue.

## Steps for reproduction

1. Start the Webstudio Devcontainer.
2. Expect the Devcontainer to start successfully without `pnpm` related
errors.
3. Verify that `pnpm` commands can be executed correctly within the
Devcontainer terminal (e.g., `pnpm --version`).

## Code Review

- [ ] hi @kof, I need you to do
  - conceptual review (architecture, feature-correctness)
  - detailed review (read every line)
  - test it on preview

## Before requesting a review

- [x] made a self-review
- [x] added inline comments where things may be not obvious (the "why",
not "what")

## Before merging

- [x] tested locally and on preview environment (preview dev login:
0000)
- [ ] updated [test
cases](https://github.com/webstudio-is/webstudio/blob/main/apps/builder/docs/test-cases.md)
document
- [ ] added tests
- [ ] if any new env variables are added, added them to `.env` file

Author: dziezdom

.devcontainer/postinstall.sh

@@ -1,36 +1,55 @@
 #!/bin/bash
 
+echo "Running postinstall.sh"
+
+# Configure FZF and bash history
 echo 'eval "$(fzf --bash)"' >> /home/node/.bashrc
+sudo mkdir -p /home/node/.local/fzf
+touch /home/node/.local/fzf/.bash_history
+echo 'export HISTFILE=/home/node/.local/fzf/.bash_history' >> "/home/node/.bashrc"
 
-mkdir -p /home/node/.local/fzf
+# Aggressively clean npm and corepack caches
+npm cache clean -f
+sudo rm -rf /tmp/corepack-cache
+sudo rm -rf /usr/local/lib/node_modules/corepack # Manually remove global corepack
 
-touch /home/node/.local/fzf/.bash_history
+# Reinstall corepack globally via npm
+npm install -g corepack@latest # Install latest corepack version
+sudo corepack enable # Re-enable corepack
 
-echo 'export HISTFILE=/home/node/.local/fzf/.bash_history' >> "/home/node/.bashrc"
+# Check corepack version after reinstall
+echo "--- Corepack version after reinstall ---"
+corepack --version
+echo "--- End corepack version check ---"
 
+
+# Prepare pnpm (again, after corepack reinstall)
+sudo corepack prepare [email protected] --activate
+
+# Go to workspace directory
 cd /workspaces/webstudio
-sudo corepack enable
-corepack install
 
+# Configure pnpm store directory
 pnpm config set store-dir $HOME/.pnpm-store
 
-
+# Clean up directories (optional)
 find . -name 'node_modules' -type d -prune -exec rm -rf '{}' +
 find . -name 'lib' -type d -prune -exec rm -rf '{}' +
 find . -name 'build' -type d -prune -exec rm -rf '{}' +
 find . -name 'dist' -type d -prune -exec rm -rf '{}' +
 find . -name '.cache' -type d -prune -exec rm -rf '{}' +
 find . -name '.pnpm-store' -type d -prune -exec rm -rf '{}' +
 
+# Install dependencies, build, and migrate
 pnpm install
 pnpm run build
 pnpm migrations migrate
 
-
+# Add git aliases
 cat << 'EOF' >> /home/node/.bashrc
-
 alias gitclean="(git remote | xargs git remote prune) && git branch -vv | egrep '('\$(git remote | xargs | sed -e 's/ /|/g')')/.*: gone]' | awk '{print \$1}'  | xargs -r git branch -D"
 alias gitrebase="git rebase --interactive main"
 EOF
 
 
+echo "postinstall.sh finished"