feat: turbostarter boilerplate

Production-ready Next.js boilerplate with:
- Runtime env validation (fail-fast on missing vars)
- Feature-gated config (S3, Stripe, email, OAuth)
- Docker + Coolify deployment pipeline
- PostgreSQL + pgvector, MinIO S3, Better Auth
- TypeScript strict mode (no ignoreBuildErrors)
- i18n (en/es), AI modules, billing, monitoring

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

tooling/github/setup/action.yml

@@ -0,0 +1,32 @@
+name: CI / Setup
+description: Common setup steps for Github Actions
+
+inputs:
+  node-version:
+    description: "Node.js version"
+    required: true
+    default: "22.x"
+  install-packages:
+    description: "Install packages"
+    required: false
+    default: "true"
+
+runs:
+  using: "composite"
+  steps:
+    - name: ✅ Checkout code
+      uses: actions/checkout@v5
+
+    - name: 🎬 Setup pnpm
+      uses: pnpm/action-setup@v4
+
+    - name: 🔨 Setup Node.js ${{ inputs.node-version }}
+      uses: actions/setup-node@v6
+      with:
+        node-version: ${{ inputs.node-version }}
+        cache: "pnpm"
+
+    - name: 🔌 Install
+      if: ${{ inputs.install-packages == 'true' }}
+      shell: bash
+      run: pnpm install