Add RedisBloom-compatible BF.* commands

[rafaelescrich]

Summary

• Adds a Value::Bloom type backed by fastbloom (database/src/bloom.rs).
• Implements RedisBloom commands used by Forja's multichain indexer: BF.RESERVE, BF.ADD, BF.MADD, BF.EXISTS, BF.MEXISTS.
• Routes bf.* commands directly (same pattern as ft.*), bypassing generic command mapping.

Behavior notes

• BF.RESERVE returns OK or ERR item exists if the key already exists.
• BF.ADD auto-creates a default filter (0.01 FPR, capacity 100) when the key is missing; returns 1 for new items, 0 if probably already present.
• BF.EXISTS on a missing key returns 0.
• Not yet implemented: scalable sub-filters (EXPANSION), BF.INFO, persistence/dump format parity with RedisBloom.

Test plan

• cargo test -p command (includes 4 Bloom-specific unit tests)
• Manual: point Forja indexer bloomfilter.type: redis at RedVector and run BF.RESERVE / BF.MADD / BF.EXISTS against a sandbox instance