Refresh blocklist cache

Manually triggers a refresh of the blocklist cache for the authenticated tenant.

This reloads all active blocklist entries from the database and rebuilds the ETS cache with optimized MapSets and combined regex patterns.

Note: Cache is also automatically refreshed:

• Every hour via Quantum scheduler
• After create/update/delete operations on blocklist entries

Use this endpoint when you need immediate cache refresh (e.g., after bulk imports).