feat(redis): add support for watch/unwatch with keyspace notifications

[saurlax]

Resolves #739

Feature: Redis keyspace notifications and watch support

• Added a watch method to the Redis driver, allowing clients to subscribe to Redis keyspace notifications for real-time updates and removals of keys. The driver attempts to enable keyspace notifications at runtime and maps Redis events to update or remove actions. An unwatch method is also provided to unsubscribe and clean up resources.
• Updated the documentation to describe the new watch/unwatch support, including configuration requirements and event mapping.

Testing

• Enhanced the Redis driver tests to use a real Redis instance if VITE_REDIS_URL is set, or fall back to ioredis-mock otherwise. Added tests for the new watch and unwatch functionality.
• Tests all passed on real Redis instance and ioredis-mock.