chore: 🚀 Migrate monorepo from Yarn to pnpm + Turbo integration + Configuration cleanup (#10165)

This PR modernizes the ZITADEL monorepo build system by migrating from
Yarn to pnpm, introducing Turbo for improved build orchestration, and
cleaning up configuration inconsistencies across all apps and packages.

### 🎯 Key Improvements

#### 📦 **Package Manager Migration (Yarn → pnpm)**
- **Performance**: Faster installs with pnpm's efficient symlink-based
node_modules structure
- **Disk space**: Significant reduction in disk usage through
content-addressable storage
- **Lockfile**: More reliable dependency resolution with pnpm-lock.yaml
- **Workspace support**: Better monorepo dependency management

#### ⚡ **Turbo Integration**
- **Build orchestration**: Dependency-aware task execution across the
monorepo
- **Intelligent caching**: Dramatically faster builds on CI/CD and local
development
- **Parallel execution**: Optimal task scheduling based on dependency
graphs
- **Vercel optimization**: Enhanced build performance and caching on
Vercel deployments

#### 🧹 **Configuration Cleanup & Unification**
- **Removed config packages**: Eliminated `@zitadel/*-config` packages
and inlined configurations
- **Simplified dependencies**: Reduced complexity in package.json files
across all apps
- **Consistent tooling**: Unified prettier, ESLint, and TypeScript
configurations
- **Standalone support**: Improved prepare-standalone.js script for
subtree deployments

### 📋 Detailed Changes

#### **🔧 Build System & Dependencies**
- ✅ Updated all package.json scripts to use `pnpm` instead of `yarn`
- ✅ Replaced `yarn.lock` with pnpm-lock.yaml and regenerated
dependencies
- ✅ Added Turbo configuration (turbo.json) to root and individual
packages
- ✅ Configured proper dependency chains: `@zitadel/proto#generate` →
`@zitadel/client#build` → `console#build`
- ✅ Added missing `@bufbuild/protobuf` dependency to console app for
TypeScript compilation

#### **🚀 CI/CD & Workflows**
- ✅ Updated all GitHub Actions workflows to use `pnpm/action-setup@v4`
- ✅ Migrated build processes to use Turbo with directory-based filters
(`--filter=./console`)
- ✅ **New**: Added `docs.yml` workflow for building documentation
locally (helpful for contributors without Vercel access)
- ✅ Fixed dependency resolution issues in lint workflows
- ✅ Ensured proto generation always runs before builds and linting

#### **📚 Documentation & Proto Generation**
- ✅ **Robust plugin management**: Enhanced plugin-download.sh with retry
logic and error handling
- ✅ **Vercel compatibility**: Fixed protoc-gen-connect-openapi plugin
availability in Vercel builds
- ✅ **API docs generation**: Resolved Docusaurus build errors with
OpenAPI plugin configuration
- ✅ **Type safety**: Improved TypeScript type extraction patterns in
Angular components

#### **🛠️ Developer Experience**
- ✅ Updated all README files to reference pnpm commands
- ✅ Improved Makefile targets to use Turbo for consistent builds
- ✅ Enhanced standalone build process for login app subtree deployments
- ✅ Added debug utilities for troubleshooting build issues

#### **🗂️ File Structure & Cleanup**
- ✅ Removed obsolete configuration packages and their references
- ✅ Cleaned up Docker files to remove non-existent package copies
- ✅ Updated workspace references and import paths
- ✅ Streamlined turbo.json configurations across all packages

### 🎉 Benefits

1. **⚡ Faster Builds**: Turbo's caching and parallel execution
significantly reduce build times
2. **🔄 Better Caching**: Improved cache hits on Vercel and CI/CD
environments
3. **🛠️ Simplified Maintenance**: Unified tooling and configuration
management
4. **📈 Developer Productivity**: Faster local development with optimized
dependency resolution
5. **🚀 Enhanced CI/CD**: More reliable and faster automated builds and
deployments
6. **📖 Better Documentation**: Comprehensive build documentation and
troubleshooting guides

### 🧪 Testing

- ✅ All apps build successfully with new pnpm + Turbo setup
- ✅ Proto generation works correctly across console, login, and docs
- ✅ GitHub Actions workflows pass with new configuration
- ✅ Vercel deployments work with enhanced plugin management
- ✅ Local development workflow verified and documented

This migration sets a solid foundation for future development while
maintaining backward compatibility and improving the overall developer
experience.

---------

Co-authored-by: Elio Bischof <elio@zitadel.com>

.github/workflows/docs.yml

@@ -0,0 +1,61 @@
+name: Build docs
+
+on:
+  workflow_call:
+    inputs:
+      node_version:
+        required: true
+        type: string
+      buf_version:
+        required: true
+        type: string
+    outputs:
+      cache_key:
+        value: ${{ jobs.build.outputs.cache_key }}
+      cache_path:
+        value: ${{ jobs.build.outputs.cache_path }}
+
+env:
+  cache_path: docs/build
+
+jobs:
+  build:
+    outputs:
+      cache_key: ${{ steps.cache.outputs.cache-primary-key }}
+      cache_path: ${{ env.cache_path }}
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/cache/restore@v4
+        timeout-minutes: 1
+        continue-on-error: true
+        id: cache
+        with:
+          key: docs-${{ hashFiles('docs', 'proto', '!docs/build', '!docs/node_modules', '!docs/protoc-gen-connect-openapi') }}
+          restore-keys: |
+            docs-
+          path: ${{ env.cache_path }}
+      - if: ${{ steps.cache.outputs.cache-hit != 'true' }}
+        uses: bufbuild/buf-setup-action@v1
+        with:
+          github_token: ${{ github.token }}
+          version: ${{ inputs.buf_version }}
+      - if: ${{ steps.cache.outputs.cache-hit != 'true' }}
+        uses: pnpm/action-setup@v4
+      - if: ${{ steps.cache.outputs.cache-hit != 'true' }}
+        uses: actions/setup-node@v4
+        with:
+          node-version: ${{ inputs.node_version }}
+          cache: "pnpm"
+          cache-dependency-path: pnpm-lock.yaml
+      - if: ${{ steps.cache.outputs.cache-hit != 'true' }}
+        name: Install dependencies
+        run: pnpm install
+      - if: ${{ steps.cache.outputs.cache-hit != 'true' }}
+        name: Build docs with Turbo
+        run: pnpm turbo build --filter=./docs
+      - if: ${{ steps.cache.outputs.cache-hit != 'true' }}
+        uses: actions/cache/save@v4
+        with:
+          path: ${{ env.cache_path }}
+          key: ${{ steps.cache.outputs.cache-primary-key }}