Module reputation 

Structs

ReputationTracker

Tracks per-IP reputation and computes a PoW-difficulty escalation for abusive sources (DOS-2). A clean / new IP contributes 0 (so well-behaved clients are never penalized); an IP that accrues handshake violations within the sliding window pays an escalating difficulty, capped at MAX_DIFFICULTY. The map is bounded (see Self::with_capacity).