Merge remote changes with local WebSocket improvements

- Combined yashksaini-coder's flow control improvements with luca's WSS features
- Preserved comprehensive WSS support, TLS configuration, and handshake timeout
- Added production-ready buffer management and connection limits
- Maintained backward compatibility with existing WebSocket functionality
- Integrated both approaches for optimal WebSocket transport implementation

tests/core/transport/test_upgrader.py

@@ -0,0 +1,27 @@
+import pytest
+
+from libp2p.custom_types import (
+    TMuxerOptions,
+    TSecurityOptions,
+)
+from libp2p.transport.upgrader import (
+    TransportUpgrader,
+)
+
+
+@pytest.mark.trio
+async def test_transport_upgrader_security_and_muxer_initialization():
+    """Test TransportUpgrader initializes security and muxer multistreams correctly."""
+    secure_transports: TSecurityOptions = {}
+    muxer_transports: TMuxerOptions = {}
+    negotiate_timeout = 15
+
+    upgrader = TransportUpgrader(
+        secure_transports, muxer_transports, negotiate_timeout=negotiate_timeout
+    )
+
+    # Verify security multistream initialization
+    assert upgrader.security_multistream.transports == secure_transports
+    # Verify muxer multistream initialization and timeout
+    assert upgrader.muxer_multistream.transports == muxer_transports
+    assert upgrader.muxer_multistream.negotiate_timeout == negotiate_timeout