feat: Fix Docker configuration and update documentation

- Fix nginx port mapping (12000:80) for single port exposure
- Remove backend port exposure (internal network only)
- Fix nginx configuration (remove invalid must-revalidate directive)
- Update README with correct setup instructions
- Update TODO.md with completed tasks and current status
- Application now running on http://localhost:12000 with production build

docker-compose.yml

@@ -33,8 +33,7 @@ services:
       UPLOAD_DIR: /app/uploads/resumes
       RUN_MIGRATIONS: "true"
       RUN_SEED: "false"
-    ports:
-      - "0.0.0.0:${BACKEND_PORT:-3001}:3001"
+    # Backend not exposed - only accessible via frontend proxy
     depends_on:
       merchantsofhope-supplyanddemandportal-database:
         condition: service_healthy
@@ -54,13 +53,12 @@ services:
     build:
       context: ./frontend
       dockerfile: Dockerfile
+      target: prod
     container_name: merchantsofhope-supplyanddemandportal-frontend
     environment:
-      HOST: ${FRONTEND_HOST:-0.0.0.0}
-      PORT: ${FRONTEND_PORT:-12000}
-      REACT_APP_API_URL: http://merchantsofhope-supplyanddemandportal-backend:3001
+      REACT_APP_API_URL: http://localhost:3001
     ports:
-      - "0.0.0.0:12000:12000"
+      - "0.0.0.0:12000:80"
     depends_on:
       - merchantsofhope-supplyanddemandportal-backend
     volumes: