node: demote routine per-peer and capacity-cap events from info/warn to debug

On a saturated public-mesh node the connection-lifecycle and capacity-cap
events fire continuously and drown out the genuinely notable INFO/WARN
lines. Demote them to debug and drop a redundant duplicate:

- FMP K-bit cutover promotion (encrypted): info -> debug
- "Connection promoted to active peer" (handshake): info -> debug, and
  remove the duplicate "Inbound peer promoted to active" line that
  shadowed it on the inbound path
- "Peer restart detected" (handshake): info -> debug
- "Peer removed and state cleaned up" (dispatch): info -> debug
- "Rejecting inbound TCP connection (max_inbound_connections reached)"
  (tcp): warn -> debug
- "Congestion detected, CE flag set on forwarded packet" (forwarding):
  warn -> debug
- "Removing peer: link dead timeout" (mmp): warn -> debug

These are expected, high-frequency conditions on a busy public node (new
and reconnecting peers, ECN CE marking, the inbound connection cap, and
link-dead churn), not operator-actionable signals.

src/node/handlers/dispatch.rs

@@ -194,7 +194,7 @@ impl Node {
         let remaining_peers: Vec<NodeAddr> = self.peers.keys().copied().collect();
         self.bloom_state.mark_all_updates_needed(remaining_peers);
 
-        info!(
+        debug!(
             peer = %self.peer_display_name(node_addr),
             link_id = %link_id,
             tree_changed = tree_changed,

src/node/handlers/encrypted.rs

@@ -5,7 +5,7 @@ use crate::node::wire::{EncryptedHeader, FLAG_CE, FLAG_KEY_EPOCH, FLAG_SP, strip
 use crate::noise::NoiseError;
 use crate::transport::ReceivedPacket;
 use std::time::Instant;
-use tracing::{debug, info, trace, warn};
+use tracing::{debug, trace, warn};
 
 /// Force-remove a peer after this many consecutive decryption failures.
 const DECRYPT_FAILURE_THRESHOLD: u32 = 20;
@@ -94,7 +94,7 @@ impl Node {
                 });
 
                 if let Some(plaintext) = pending_plaintext {
-                    info!(
+                    debug!(
                         peer = %display_name,
                         "Peer new-epoch frame authenticated, K-bit flip promoting new session"
                     );

src/node/handlers/forwarding.rs

@@ -106,7 +106,7 @@ impl Node {
                 .unwrap_or(true);
             if should_log {
                 self.last_congestion_log = Some(now);
-                warn!(next_hop = %next_hop_addr, "Congestion detected, CE flag set on forwarded packet");
+                debug!(next_hop = %next_hop_addr, "Congestion detected, CE flag set on forwarded packet");
             }
         }
 

src/node/handlers/handshake.rs

@@ -248,7 +248,7 @@ impl Node {
             match (existing_epoch, new_epoch) {
                 (Some(existing), Some(new)) if existing != new => {
                     // Epoch mismatch — peer restarted. Tear down stale session.
-                    info!(
+                    debug!(
                         peer = %self.peer_display_name(&peer_node_addr),
                         "Peer restart detected (epoch mismatch), removing stale session"
                     );
@@ -510,12 +510,9 @@ impl Node {
                         if let Some(peer) = self.peers.get_mut(&node_addr) {
                             peer.set_handshake_msg2(wire_msg2.clone());
                         }
-                        debug!(
-                            peer = %self.peer_display_name(&node_addr),
-                            link_id = %link_id,
-                            our_index = %our_index,
-                            "Inbound peer promoted to active"
-                        );
+                        // Promotion is logged once by `promote_connection`
+                        // ("Connection promoted to active peer"); no separate
+                        // inbound-path line.
                         // Send initial tree announce to new peer
                         if let Err(e) = self.send_tree_announce_to_peer(&node_addr).await {
                             debug!(peer = %self.peer_display_name(&node_addr), error = %e, "Failed to send initial TreeAnnounce");
@@ -1166,7 +1163,7 @@ impl Node {
             self.retry_pending.remove(&peer_node_addr);
             self.register_identity(peer_node_addr, verified_identity.pubkey_full());
 
-            info!(
+            debug!(
                 peer = %self.peer_display_name(&peer_node_addr),
                 link_id = %link_id,
                 our_index = %our_index,

src/node/handlers/mmp.rs

@@ -573,7 +573,7 @@ impl Node {
             .unwrap_or(0);
 
         for addr in &dead_peers {
-            warn!(
+            debug!(
                 peer = %self.peer_display_name(addr),
                 timeout_secs = self.config.node.link_dead_timeout_secs,
                 "Removing peer: link dead timeout"

src/transport/tcp/mod.rs

@@ -801,7 +801,7 @@ async fn accept_loop(
                 // operator-facing inbound cap.
                 if stats.pool_inbound_count() >= max_inbound as u64 {
                     stats.record_connection_rejected();
-                    warn!(
+                    debug!(
                         transport_id = %transport_id,
                         peer_addr = %peer_addr,
                         max = max_inbound,