Handles Redis-compatible Bloom filter commands.

Write commands (BF.RESERVE, BF.ADD, BF.MADD) route through Raft via store.prob_write so that mutations are replicated to follower nodes. Read commands (BF.EXISTS, BF.MEXISTS, BF.CARD, BF.INFO) use stateless pread NIFs directly on the local file — no Raft, no mmap, no resource caching.

Supported Commands

• BF.RESERVE key error_rate capacity -- creates a new Bloom filter
• BF.ADD key element -- adds an element (auto-creates with defaults if missing)
• BF.MADD key element [element ...] -- adds multiple elements
• BF.EXISTS key element -- checks if an element may exist
• BF.MEXISTS key element [element ...] -- checks multiple elements
• BF.CARD key -- returns the number of elements added
• BF.INFO key -- returns filter metadata