feat: API Gateway (Express 5 + Prisma + Monday) y conexion de apps al API

- api-gateway: servicio Monday (retry 429/complejidad, paginacion cursor,
  column IDs por titulo), endpoints unidades/cotizaciones/clientes/planes,
  webhook con handshake challenge, Prisma SQLite dev, 55 tests
- cotizador: inventario desde /api/unidades con fallback a seed
- alta-clientes: POST /api/clientes + upload multipart de documentos
- cobranza: persistencia via API con respaldo offline en localStorage
- .env.example con board IDs del workspace Frasa-CAS

api-gateway/package.json

@@ -0,0 +1,35 @@
+{
+  "name": "frasa-api-gateway",
+  "version": "0.1.0",
+  "private": true,
+  "description": "API Gateway del ecosistema FRASA: conecta las apps web con Monday.com y da persistencia",
+  "type": "module",
+  "engines": {
+    "node": ">=22"
+  },
+  "scripts": {
+    "dev": "tsx watch src/index.ts",
+    "build": "tsc -p tsconfig.json",
+    "start": "node dist/index.js",
+    "test": "vitest run",
+    "prisma:migrate": "prisma migrate dev"
+  },
+  "dependencies": {
+    "@prisma/client": "^6.14.0",
+    "cors": "^2.8.5",
+    "dotenv": "^16.4.5",
+    "express": "^5.1.0",
+    "multer": "^2.0.2",
+    "zod": "^3.25.76"
+  },
+  "devDependencies": {
+    "@types/cors": "^2.8.19",
+    "@types/express": "^5.0.3",
+    "@types/multer": "^2.0.0",
+    "@types/node": "^22.15.0",
+    "prisma": "^6.14.0",
+    "tsx": "^4.20.3",
+    "typescript": "^5.9.2",
+    "vitest": "^3.2.4"
+  }
+}