Dev update: provably-fair — verifiable spins (commit-reveal)

We rolled out provably-fair: before a series of spins, the server publishes a hash of the server seed. Each spin outcome is deterministically derived from serverSeed + clientSeed + nonce (HMAC-SHA256, no modulo bias). After the seed is rotated, it is revealed, and anyone can recalculate past spins via /api/fair/verify. RTP remains unchanged. A detailed breakdown of the mechanics is in the blog: /blog/provably-fair-slots