diff --git a/crates/wzp-relay/src/audio_scorer.rs b/crates/wzp-relay/src/audio_scorer.rs
index c7abb47..1b5f656 100644
--- a/crates/wzp-relay/src/audio_scorer.rs
+++ b/crates/wzp-relay/src/audio_scorer.rs
@@ -20,7 +20,7 @@ const SILENCE_SIZE_THRESHOLD: usize = 16;
 /// Observation window for bitrate tracking.
 const BITRATE_WINDOW_SECS: u64 = 30;
 
-/// Number of payload-size histogram bins.
+// Number of payload-size histogram bins.
 // (SIZE_BINS reserved for future histogram-based bimodality)
 
 /// Verdict produced by the scorer after sufficient observation.
@@ -190,7 +190,7 @@ impl AudioScorer {
             }
         }
 
-        Some(score.max(0.0).min(1.0))
+        Some(score.clamp(0.0, 1.0))
     }
 
     /// Map legitimacy score to a [`Verdict`].
@@ -299,7 +299,7 @@ impl AudioScorer {
         let large = self.size_samples.len() - small;
         let total = self.size_samples.len() as f64;
         let p_small = small as f64 / total;
-        let p_large = large as f64 / total;
+        let _p_large = large as f64 / total;
         // Max bimodality when both bins are equally populated (~0.5 each)
         let bimodality = 1.0 - (p_small - 0.5).abs() * 2.0;
         Some(bimodality)
diff --git a/crates/wzp-relay/src/conformance.rs b/crates/wzp-relay/src/conformance.rs
index 5741486..04763b9 100644
--- a/crates/wzp-relay/src/conformance.rs
+++ b/crates/wzp-relay/src/conformance.rs
@@ -27,6 +27,10 @@ pub enum Violation {
     RateCapExceeded,
 }
 
+/// Error type returned when a [`TokenBucket`] does not hold enough tokens.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct TokenExhausted;
+
 /// Simple token bucket for per-session rate capping (Tier E).
 ///
 /// Tokens represent bytes.  The bucket refills at `refill_per_sec` bytes per
@@ -61,9 +65,9 @@ impl TokenBucket {
     /// Attempt to consume `bytes` from the bucket.
     ///
     /// Refills based on elapsed time since the last call, then deducts the
-    /// cost.  Returns `Ok(())` if enough tokens were available, `Err(())`
-    /// otherwise.
-    pub fn try_consume(&mut self, bytes: u64, now: Instant) -> Result<(), ()> {
+    /// cost.  Returns `Ok(())` if enough tokens were available,
+    /// `Err(TokenExhausted)` otherwise.
+    pub fn try_consume(&mut self, bytes: u64, now: Instant) -> Result<(), TokenExhausted> {
         let elapsed = now.duration_since(self.last_refill);
         self.last_refill = now;
         self.tokens += elapsed.as_secs_f64() * self.refill_per_sec as f64;
@@ -74,7 +78,7 @@ impl TokenBucket {
             self.tokens -= bytes as f64;
             Ok(())
         } else {
-            Err(())
+            Err(TokenExhausted)
         }
     }
 }
diff --git a/crates/wzp-relay/src/presence.rs b/crates/wzp-relay/src/presence.rs
index 85827ac..e17b2ed 100644
--- a/crates/wzp-relay/src/presence.rs
+++ b/crates/wzp-relay/src/presence.rs
@@ -63,6 +63,12 @@ pub struct PresenceRegistry {
     peers: HashMap<SocketAddr, PeerRelay>,
 }
 
+impl Default for PresenceRegistry {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl PresenceRegistry {
     /// Create an empty registry.
     pub fn new() -> Self {
diff --git a/crates/wzp-relay/src/response_policy.rs b/crates/wzp-relay/src/response_policy.rs
index e990d63..b7a3a34 100644
--- a/crates/wzp-relay/src/response_policy.rs
+++ b/crates/wzp-relay/src/response_policy.rs
@@ -41,8 +41,6 @@ pub enum Action {
 pub struct ResponsePolicy {
     /// `(fingerprint, violation_code)` → last abusive instant.
     cooldowns: HashMap<(String, ViolationCode), Instant>,
-    /// Cool-down duration for first-time abuse.
-    cooldown_duration: Duration,
     /// Block duration for repeat abuse.
     block_duration: Duration,
 }
@@ -51,8 +49,7 @@ impl ResponsePolicy {
     pub fn new() -> Self {
         Self {
             cooldowns: HashMap::new(),
-            cooldown_duration: Duration::from_secs(3600), // 1 h
-            block_duration: Duration::from_secs(86400),   // 24 h
+            block_duration: Duration::from_secs(86400), // 24 h
         }
     }