diff --git a/.gitignore b/.gitignore
index c2b1d85..147d118 100644
--- a/.gitignore
+++ b/.gitignore
@@ -73,3 +73,7 @@ tools/license_private.key
 
 # Local config backups
 *.env.bak
+
+# Local tooling artifacts
+.claude/screenshots/
+.playwright-mcp/
diff --git a/CLAUDE.md b/CLAUDE.md
index 8ff953e..da69b3f 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -5,8 +5,8 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 ## System Overview
 
 ScalesApp is a three-tier weighing scale management system with real-time data synchronization:
-- **Django Backend** (REST API + Server-Sent Events) on port 8000
-- **React Frontend** (SPA) on port 3000
+- **Django Backend** (REST API + Server-Sent Events) on port 8002
+- **React Frontend** (SPA) on port 5172
 - **Serial Bridge** (Flask SSE server) on port 5000 for COM port reading
 
 ## Development Commands
@@ -25,8 +25,8 @@ python manage.py migrate
 python manage.py createsuperuser
 
 # Run server
-python manage.py runserver  # Development (WSGI)
-uvicorn scalesapp.asgi:application --reload  # Development (ASGI - for SSE)
+python manage.py runserver 8002  # Development (WSGI)
+uvicorn scalesapp.asgi:application --reload --port 8002  # Development (ASGI - for SSE)
 
 # Testing (when implemented)
 python manage.py test
@@ -38,7 +38,7 @@ python manage.py test api.tests.test_models  # Single test file
 ```bash
 cd frontend
 npm install
-npm start      # Development server
+npm start      # Development server (port from frontend/.env, currently 5172)
 npm run build  # Production build
 npm test       # Run tests
 ```
@@ -253,7 +253,8 @@ Element (base class)
 - SSE connection authenticated via query param: `/sse-connect/?token=<jwt>` or Authorization header
 
 **CORS Configuration:**
-- Allowed origins: http://localhost:3000, http://127.0.0.1:3000, http://localhost:5174
+- Allowed origins (default): http://localhost:5172, http://127.0.0.1:5172, http://localhost:3000, http://127.0.0.1:3000, http://localhost:5174, http://127.0.0.1:5174
+- Override with the `CORS_ALLOWED_ORIGINS` env var (comma-separated)
 - Credentials allowed (for cookies if needed)
 
 **User Roles:**
@@ -316,7 +317,8 @@ DB_PORT=5432
 
 **Frontend:** `frontend/.env`
 ```
-REACT_APP_API_URL=http://localhost:8000
+PORT=5172
+REACT_APP_API_URL=http://localhost:8002
 ```
 
 **Serial Bridge:** `serial_bridge/.env`
@@ -330,11 +332,11 @@ DEBUG=False
 
 ## Running the Full Application
 
-1. Start Django: `cd backend && python manage.py runserver`
+1. Start Django: `cd backend && python manage.py runserver 8002`
 2. Start Serial Bridge: `cd serial_bridge && python app.py`
 3. Start React: `cd frontend && npm start`
 
-For SSE to work properly in Django, use uvicorn instead: `uvicorn scalesapp.asgi:application --reload`
+For SSE to work properly in Django, use uvicorn instead: `uvicorn scalesapp.asgi:application --reload --port 8002`
 
 ## Common Patterns