Add stress and manual benchmark tests for handshake protocols

- Introduced `handshake_real_bug_stress_tests.rs` to validate TLS and MTProto handshake behaviors under various conditions, including ALPN rejection and session ID handling.
- Implemented tests to ensure replay cache integrity and proper handling of malicious input without panicking.
- Added `handshake_timing_manual_bench_tests.rs` for performance benchmarking of user authentication paths, comparing preferred user handling against full user scans in both MTProto and TLS contexts.
- Included timing-sensitive tests to measure the impact of SNI on handshake performance.

src/proxy/handshake.rs

@@ -605,16 +605,6 @@ where
         }
     };
 
-    // Replay tracking is applied only after successful authentication to avoid
-    // letting unauthenticated probes evict valid entries from the replay cache.
-    let digest_half = &validation.digest[..tls::TLS_DIGEST_HALF_LEN];
-    if replay_checker.check_and_add_tls_digest(digest_half) {
-        auth_probe_record_failure(peer.ip(), Instant::now());
-        maybe_apply_server_hello_delay(config).await;
-        warn!(peer = %peer, "TLS replay attack detected (duplicate digest)");
-        return HandshakeResult::BadClient { reader, writer };
-    }
-
     let secret = match secrets.iter().find(|(name, _)| *name == validation.user) {
         Some((_, s)) => s,
         None => {
@@ -670,6 +660,16 @@ where
         None
     };
 
+    // Replay tracking is applied only after full policy validation (including
+    // ALPN checks) so rejected handshakes cannot poison replay state.
+    let digest_half = &validation.digest[..tls::TLS_DIGEST_HALF_LEN];
+    if replay_checker.check_and_add_tls_digest(digest_half) {
+        auth_probe_record_failure(peer.ip(), Instant::now());
+        maybe_apply_server_hello_delay(config).await;
+        warn!(peer = %peer, "TLS replay attack detected (duplicate digest)");
+        return HandshakeResult::BadClient { reader, writer };
+    }
+
     let response = if let Some((cached_entry, use_full_cert_payload)) = cached {
         emulator::build_emulated_server_hello(
             secret,
@@ -979,6 +979,22 @@ mod saturation_poison_security_tests;
 #[path = "tests/handshake_auth_probe_hardening_adversarial_tests.rs"]
 mod auth_probe_hardening_adversarial_tests;
 
+#[cfg(test)]
+#[path = "tests/handshake_advanced_clever_tests.rs"]
+mod advanced_clever_tests;
+
+#[cfg(test)]
+#[path = "tests/handshake_more_clever_tests.rs"]
+mod more_clever_tests;
+
+#[cfg(test)]
+#[path = "tests/handshake_real_bug_stress_tests.rs"]
+mod real_bug_stress_tests;
+
+#[cfg(test)]
+#[path = "tests/handshake_timing_manual_bench_tests.rs"]
+mod timing_manual_bench_tests;
+
 /// Compile-time guard: HandshakeSuccess holds cryptographic key material and
 /// must never be Copy.  A Copy impl would allow silent key duplication,
 /// undermining the zeroize-on-drop guarantee.