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/vitest/turbo.json

@@ -0,0 +1,22 @@
+{
+  "extends": ["//"],
+  "tasks": {
+    "test:coverage:collect": {
+      "cache": false
+    },
+    "test:coverage:merge": {
+      "dependsOn": ["test:coverage:collect"],
+      "inputs": ["coverage/raw/**"],
+      "outputs": ["coverage/merged/**"]
+    },
+    "test:coverage": {
+      "dependsOn": ["test:coverage:merge"],
+      "inputs": ["coverage/merge"],
+      "outputs": ["coverage/report/**"]
+    },
+    "test:coverage:view": {
+      "dependsOn": ["test:coverage"],
+      "cache": false
+    }
+  }
+}