初始提交：terminalX 可运行态（M0/M1/M1.5 已真机验证）

- M0: libghostty SSH 终端（渲染/输入/连接）+ 白屏修复(OutputGate) + 会话状态机/自动重连
- M1: tsnet 用户态组网 + SSH-over-tsnet(fd 桥)，shell 级真机验证；R5(Go+gvisor+C+++Swift 同进程) retire
- M1.5: tmux -CC 原生 tab（MVP）
- 结构: packages/(TXCore·TXTransport), apps/TerminalX, vendor/(libghostty-spm/libssh2/mbedtls/tsnet-bridge), artifacts/
- 文档: CLAUDE.md + docs/HANDOFF.md（新会话入口）
- 环境: 认证代理→依赖 vendor 本地化；Go 在 ~/.local/go；仅模拟器/未签名
- 待续: M2 mosh, tmux 多 pane, M4 安全(host key/SE)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

vendor/libssh2/docs/libssh2_session_method_pref.3

@@ -0,0 +1,41 @@
+.\" Copyright (C) The libssh2 project and its contributors.
+.\" SPDX-License-Identifier: BSD-3-Clause
+.TH libssh2_session_method_pref 3 "1 Jun 2007" "libssh2 0.15" "libssh2"
+.SH NAME
+libssh2_session_method_pref - set preferred key exchange method
+.SH SYNOPSIS
+.nf
+#include <libssh2.h>
+
+int
+libssh2_session_method_pref(LIBSSH2_SESSION *session,
+                            int method_type, const char *prefs);
+.fi
+.SH DESCRIPTION
+\fIsession\fP - Session instance as returned by
+.BR libssh2_session_init_ex(3)
+
+\fImethod_type\fP - One of the Method Type constants.
+
+\fIprefs\fP - Coma delimited list of preferred methods to use with
+the most preferred listed first and the least preferred listed last.
+If a method is listed which is not supported by libssh2 it will be
+ignored and not sent to the remote host during protocol negotiation.
+
+Set preferred methods to be negotiated. These
+preferences must be set prior to calling
+.BR libssh2_session_handshake(3)
+as they are used during the protocol initiation phase.
+.SH RETURN VALUE
+Return 0 on success or negative on failure. It returns
+LIBSSH2_ERROR_EAGAIN when it would otherwise block. While
+LIBSSH2_ERROR_EAGAIN is a negative number, it is not really a failure per se.
+.SH ERRORS
+\fILIBSSH2_ERROR_INVAL\fP - The requested method type was invalid.
+
+\fILIBSSH2_ERROR_ALLOC\fP - An internal memory allocation call failed.
+
+\fILIBSSH2_ERROR_METHOD_NOT_SUPPORTED\fP - The requested method is not supported.
+.SH SEE ALSO
+.BR libssh2_session_init_ex(3)
+.BR libssh2_session_handshake(3)