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/protobuf/protobuf_release.bzl

@@ -0,0 +1,50 @@
+"""
+Generates package naming variables for use with rules_pkg.
+"""
+
+load("@rules_pkg//:providers.bzl", "PackageVariablesInfo")
+load("@bazel_tools//tools/cpp:toolchain_utils.bzl", "find_cpp_toolchain")
+load(":protobuf_version.bzl", "PROTOC_VERSION")
+
+def _package_naming_impl(ctx):
+  values = {}
+  values["version"] = PROTOC_VERSION
+
+  # infer from the current cpp toolchain.
+  toolchain = find_cpp_toolchain(ctx)
+  cpu = toolchain.cpu
+  system_name = toolchain.target_gnu_system_name
+
+  # rename cpus to match what we want artifacts to be
+  if cpu == "systemz":
+    cpu = "s390_64"
+  elif cpu == "aarch64":
+    cpu = "aarch_64"
+  elif cpu == "ppc64":
+    cpu = "ppcle_64"
+
+  # use the system name to determine the os and then create platform names
+  if "apple" in system_name:
+    values["platform"] = "osx-" + cpu
+  elif "linux" in system_name:
+    values["platform"] = "linux-" + cpu
+  elif "mingw" in system_name:
+    if cpu == "x86_64":
+      values["platform"] = "win64"
+    else:
+      values["platform"] = "win32"
+  else:
+    values["platform"] = "unknown"
+
+  return PackageVariablesInfo(values = values)
+
+
+package_naming = rule(
+  implementation = _package_naming_impl,
+    attrs = {
+      # Necessary data dependency for find_cpp_toolchain.
+      "_cc_toolchain": attr.label(default = Label("@bazel_tools//tools/cpp:current_cc_toolchain")),
+    },
+    toolchains = ["@bazel_tools//tools/cpp:toolchain_type"],
+    incompatible_use_toolchain_transition = True,
+)