fix: Prevent nodemon restarts during policy creation

- Move temp directory outside app folder to /tmp/minio-webui-temp
- Add nodemon.json to ignore temp, logs, and node_modules
- Add TEMP_DIR environment variable configuration
- Add cleanup routine for old temporary policy files (>1 hour)
- Update both dev and production Dockerfiles
- Update docker-compose configurations

This fixes the 500 error during QuickStartWizard policy creation
caused by nodemon restarting when temporary files were created.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

docker-compose.dev.yml

@@ -13,7 +13,7 @@ services:
       NODE_ENV: development
       PORT: 7510
       LOG_DIR: /app/logs
-      TEMP_DIR: /app/temp
+      TEMP_DIR: /tmp/minio-webui-temp
       LOG_LEVEL: debug
     env_file:
       - .env
@@ -24,7 +24,7 @@ services:
       - ./backend/package.json:/app/package.json
       - ./backend/package-lock.json:/app/package-lock.json
       - backend-logs:/app/logs
-      - backend-temp:/app/temp
+      - backend-temp:/tmp/minio-webui-temp
       - mc-config:/home/node/.mc
     depends_on:
       - redis