fix: Resolve backend permission errors for temp and logs directories

- Fix MinIO service temp directory path (was going to /temp instead of /app/temp)
- Add TEMP_DIR environment variable support
- Make audit logger optional in development mode to avoid permission issues
- Ensure log directory exists before creating loggers
- Update docker-entrypoint.sh to create temp directory
- Create backend/temp directory with .gitkeep
- Update .gitignore to exclude temp files but keep directory structure

This fixes the EACCES permission errors that were causing the backend to restart.

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

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

.gitignore

@@ -43,6 +43,8 @@ coverage/
 temp/
 tmp/
 *.tmp
+backend/temp/*
+!backend/temp/.gitkeep
 
 # MinIO configuration
 .mc/