Phase 1.2: SMB3 encryption negotiation + session state

- Add encryption_supported and encryption_cipher to Connection state
- Add encryption_key and encryption_enabled to Session state
- Add EncryptionCapabilities context to NegotiateResponse (SMB 3.1.1)
- Derive encryption_key from session_base_key in session_setup
- Export derive_encryption_key as public method
- Fix Session::new() signature with 8 parameters
- All encryption tests pass (3 passed)

vendor/smb-server/src/tests/dynamic_config.rs

@@ -38,7 +38,7 @@ async fn register_session(
     ));
     state.active_connections.register(&conn).await;
 
-    let session = Session::new(1, identity, [0; 16], [0; 16], false, None);
+    let session = Session::new(1, identity, [0; 16], [0; 16], None, false, false, None);
     let session = Arc::new(tokio::sync::RwLock::new(session));
     let share = state.find_share(share_name).await.expect("share");
     let tree = Arc::new(tokio::sync::RwLock::new(TreeConnect::new(