fix: eliminate all compiler warnings

- Remove unused imports across multiple modules
- Add #![allow(dead_code)] for public API items preserved for future use
- Add #![allow(deprecated)] for rand::Rng::gen_range usage
- Add #![allow(unused_assignments)] in main.rs
- Add #![allow(unreachable_code)] in network/stun.rs
- Prefix unused variables with underscore (_ip_tracker, _prefer_ipv6)
- Fix unused_must_use warning in tls_front/cache.rs

This ensures clean compilation without warnings while preserving
public API items that may be used in the future.

src/transport/middle_proxy/health.rs

@@ -14,6 +14,7 @@ use super::MePool;
 
 const HEALTH_INTERVAL_SECS: u64 = 1;
 const JITTER_FRAC_NUM: u64 = 2; // jitter up to 50% of backoff
+#[allow(dead_code)]
 const MAX_CONCURRENT_PER_DC_DEFAULT: usize = 1;
 
 pub async fn me_health_monitor(pool: Arc<MePool>, rng: Arc<SecureRandom>, _min_connections: usize) {

src/transport/middle_proxy/mod.rs

@@ -17,8 +17,10 @@ mod wire;
 use bytes::Bytes;
 
 pub use health::me_health_monitor;
+#[allow(unused_imports)]
 pub use ping::{run_me_ping, format_sample_line, MePingReport, MePingSample, MePingFamily};
 pub use pool::MePool;
+#[allow(unused_imports)]
 pub use pool_nat::{stun_probe, detect_public_ip};
 pub use registry::ConnRegistry;
 pub use secret::fetch_proxy_secret;

src/transport/middle_proxy/ping.rs

@@ -24,6 +24,7 @@ pub struct MePingSample {
 }
 
 #[derive(Debug, Clone)]
+#[allow(dead_code)]
 pub struct MePingReport {
     pub dc: i32,
     pub family: MePingFamily,

src/transport/middle_proxy/pool.rs

@@ -36,6 +36,7 @@ pub struct MeWriter {
     pub allow_drain_fallback: Arc<AtomicBool>,
 }
 
+#[allow(dead_code)]
 pub struct MePool {
     pub(super) registry: Arc<ConnRegistry>,
     pub(super) writers: Arc<RwLock<Vec<MeWriter>>>,
@@ -992,6 +993,7 @@ impl MePool {
 
 }
 
+#[allow(dead_code)]
 fn hex_dump(data: &[u8]) -> String {
     const MAX: usize = 64;
     let mut out = String::with_capacity(data.len() * 2 + 3);

src/transport/middle_proxy/pool_nat.rs

@@ -1,7 +1,7 @@
 use std::net::{IpAddr, Ipv4Addr};
 use std::time::Duration;
 
-use tracing::{info, warn, debug};
+use tracing::{info, warn};
 
 use crate::error::{ProxyError, Result};
 use crate::network::probe::is_bogon;
@@ -9,11 +9,14 @@ use crate::network::stun::{stun_probe_dual, IpFamily, StunProbeResult};
 
 use super::MePool;
 use std::time::Instant;
+
+#[allow(dead_code)]
 pub async fn stun_probe(stun_addr: Option<String>) -> Result<crate::network::stun::DualStunResult> {
     let stun_addr = stun_addr.unwrap_or_else(|| "stun.l.google.com:19302".to_string());
     stun_probe_dual(&stun_addr).await
 }
 
+#[allow(dead_code)]
 pub async fn detect_public_ip() -> Option<IpAddr> {
     fetch_public_ipv4_with_retry().await.ok().flatten().map(IpAddr::V4)
 }

src/transport/middle_proxy/registry.rs

@@ -21,6 +21,7 @@ pub enum RouteResult {
 }
 
 #[derive(Clone)]
+#[allow(dead_code)]
 pub struct ConnMeta {
     pub target_dc: i16,
     pub client_addr: SocketAddr,
@@ -29,6 +30,7 @@ pub struct ConnMeta {
 }
 
 #[derive(Clone)]
+#[allow(dead_code)]
 pub struct BoundConn {
     pub conn_id: u64,
     pub meta: ConnMeta,
@@ -167,6 +169,7 @@ impl ConnRegistry {
         out
     }
 
+    #[allow(dead_code)]
     pub async fn get_meta(&self, conn_id: u64) -> Option<ConnMeta> {
         let inner = self.inner.read().await;
         inner.meta.get(&conn_id).cloned()

src/transport/middle_proxy/secret.rs

@@ -1,5 +1,3 @@
-use std::time::Duration;
-
 use tracing::{debug, info, warn};
 use std::time::SystemTime;
 use httpdate;