Rate Limiting and Throttling for File Operations

[DenizAltunkapan]

Implement configurable rate limits for upload, download, and listing operations to prevent abuse and stabilize performance. Return HTTP 429 responses with clear headers when limits are exceeded, and expose metrics/logs for monitoring. Support per-user, per-IP, and global policies using a standard approach (e.g., Bucket4j or Spring-based filters). Provide configuration via properties and environment variables. Add tests covering normal, burst, and throttled scenarios.