feat: implement secure multi-tenancy, RBAC, and premium dark mode

- Enforced tenant isolation and Role-Based Access Control across all API routes

- Implemented secure profile avatar upload using multer and UUIDs

- Redesigned UI with a premium "Onyx & Gold" Charcoal dark mode

- Added Funnel Stage and Origin filters to Dashboard and User Detail pages

- Replaced "Referral" with "Indicação" across the platform and database

- Optimized Dockerfile and local environment setup for reliable deployments

- Fixed frontend syntax errors and improved KPI/Chart visualizations

docker-compose.local.yml

@@ -18,7 +18,9 @@ services:
       - MAIL_FROM=${MAIL_FROM}
     volumes:
       - ./dist:/app/dist # Map local build to container
-      - ./backend:/app/backend # Map backend source to container
+      - ./backend/index.js:/app/index.js
+      - ./backend/db.js:/app/db.js
+    command: ["node", "index.js"]
     depends_on:
       - db