feat: 完成 M2 mosh（LAN + tsnet 端到端验证）

- mosh(blinksh/ios C++)+protobuf-lite 交叉编译为 MoshCore.xcframework
  （CommonCrypto 后端、含 arm64 模拟器 slice；绕 autotools 用 CMake 直编 + 手写 config.h）
- tsnet 桥新增 UDP relay（StartMoshRelay：loopback↔tsnet.Dial 逐包搬运）
- MoshSession（pipe↔FILE*/pthread/SIGWINCH）+ MoshConnectScanner（TXCore，+4 单测=39）
- SSHTerminalModel 编排：SSH 引导 mosh-server→解析 MOSH CONNECT→relay→mosh 接管
- LAN 直连 + mosh-over-tsnet 均端到端验证通过，R1(tsnet UDP 数据报语义) 证伪

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

vendor/mosh/man/mosh-client.1

@@ -0,0 +1,96 @@
+.\"                                      Hey, EMACS: -*- nroff -*-
+.\" First parameter, NAME, should be all caps
+.\" Second parameter, SECTION, should be 1-8, maybe w/ subsection
+.\" other parameters are allowed: see man(7), man(1)
+.TH MOSH 1 "February 2012"
+.\" Please adjust this date whenever revising the manpage.
+.\"
+.\" Some roff macros, for reference:
+.\" .nh        disable hyphenation
+.\" .hy        enable hyphenation
+.\" .ad l      left justify
+.\" .ad b      justify to both left and right margins
+.\" .nf        disable filling
+.\" .fi        enable filling
+.\" .br        insert line break
+.\" .sp <n>    insert n+1 empty lines
+.\" for manpage-specific macros, see man(7)
+.SH NAME
+mosh-client \- client-side helper for mosh
+.SH SYNOPSIS
+MOSH_KEY=KEY
+.B mosh-client 
+IP PORT
+.br
+.B mosh-client 
+\-c
+.br
+.SH DESCRIPTION
+\fBmosh-client\fP is a helper program for the 
+.BR mosh (1)
+remote terminal application.
+
+\fBmosh\fP itself is a setup script that establishes an SSH
+connection, runs the server-side helper \fBmosh-server\fP,
+and collects the server's port number and session key.
+
+\fBmosh\fP then executes \fBmosh-client\fP with the server's IP
+address, port, and session key. \fBmosh-client\fP runs for
+the lifetime of the connection.
+
+The 22-byte base64 session key given by \fBmosh-server\fP is supplied
+in the MOSH_KEY environment variable. This represents a 128-bit AES
+key that protects the integrity and confidentiality of the session.
+
+For constructing new setup wrappers for remote execution facilities
+other than SSH, it may be necessary to invoke \fBmosh-client\fP
+directly.
+
+With the \-c option, \fBmosh-client\fP instead prints the number of colors
+of the terminal given by the TERM environment variable.
+
+.SH ENVIRONMENT VARIABLES
+
+.TP
+.B MOSH_KEY
+This variable must be set, and must contain a Base64-encoded cryptographic key from
+.BR mosh-server (1).
+
+.TP
+.B MOSH_ESCAPE_KEY
+See
+.BR mosh (1).
+
+.TP
+.B MOSH_PREDICTION_DISPLAY
+Controls local echo as described in
+.BR mosh (1).
+
+.TP
+.B MOSH_TITLE_NOPREFIX
+See
+.BR mosh (1).
+
+
+.SH SEE ALSO
+.BR mosh (1),
+.BR mosh-server (1).
+
+Project home page:
+.I http://mosh.mit.edu
+
+.br
+.SH AUTHOR
+mosh was written by Keith Winstein <mosh-devel@mit.edu>.
+.SH BUGS
+Please report bugs to \fImosh-devel@mit.edu\fP. Users may also subscribe
+to the
+.nh
+.I mosh-users@mit.edu
+.hy
+mailing list, at
+.br
+.nh
+.I http://mailman.mit.edu/mailman/listinfo/mosh-users
+.hy
+.