Add port troubleshooting and fix script

- Add fix-port.bat to handle 'port already in use' errors
- Detect blocking process and kill it, or prompt to use different port
- Updated start.bat to detect startup failures and offer fix
- Updated README.md with troubleshooting guide for port conflicts

Users can now easily resolve port 7777 conflicts by running fix-port.bat
or using --port override on the CLI.

Co-authored-by: Cursor <cursoragent@cursor.com>

server/start.bat

@@ -48,4 +48,17 @@ echo.
 
 python consumer_server_cli.py serve --config commonwealth-server.json
 
+REM Check if the error was port in use
+if errorlevel 1 (
+    echo.
+    echo Server failed to start. If you see "Only one usage of each socket address"
+    echo error, the port may already be in use.
+    echo.
+    choice /C YN /N /M "Would you like to fix the port issue? (Y/N): "
+    if !errorlevel!==1 (
+        echo.
+        call fix-port.bat
+    )
+)
+
 pause