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_channel_subsystem.3

@@ -0,0 +1,21 @@
+.\" Copyright (C) The libssh2 project and its contributors.
+.\" SPDX-License-Identifier: BSD-3-Clause
+.TH libssh2_channel_subsystem 3 "20 Feb 2010" "libssh2 1.2.4" "libssh2"
+.SH NAME
+libssh2_channel_subsystem - convenience macro for \fIlibssh2_channel_process_startup(3)\fP calls
+.SH SYNOPSIS
+.nf
+#include <libssh2.h>
+
+int
+libssh2_channel_subsystem(LIBSSH2_CHANNEL *channel, const char *subsystem);
+.fi
+.SH DESCRIPTION
+This is a macro defined in a public libssh2 header file that is using the
+underlying function \fIlibssh2_channel_process_startup(3)\fP.
+.SH RETURN VALUE
+See \fIlibssh2_channel_process_startup(3)\fP
+.SH ERRORS
+See \fIlibssh2_channel_process_startup(3)\fP
+.SH SEE ALSO
+.BR libssh2_channel_process_startup(3)