Enhance the configuration diff logic to include detection and reporting of `prefix` changes for all model types. Update related struct naming for consistency across the watcher module.
Introduce formatProxyURL helper to sanitize proxy addresses before
logging, stripping credentials and path components while preserving
host information. Rework model hash computation to sort and deduplicate
name/alias pairs with case normalization, ensuring consistent output
regardless of input ordering. Add signature-based identification for
anonymous OpenAI-compatible provider entries to maintain stable keys
across configuration reloads. Replace direct stdout prints with
structured logger calls for file change notifications.
Break out config diffing, hashing, and OpenAI compatibility utilities into a dedicated diff package, update watcher to consume them, and add comprehensive tests for diff logic and watcher behavior.
