feat(installer): support Linux hosts with XDG data root and ss port probe

- platform gate accepts Darwin and Linux; other platforms are refused
- default install root follows each platform's convention
  (~/Library/Application Support vs ~/.local/share)
- LAN IP discovery uses ip -4/hostname -I on Linux, ipconfig on macOS
- port occupancy checks fall back from lsof to ss
- API process gets MULTI_SIMADMIN_SECRET_BACKEND pinned per platform
- README documents the per-platform secret storage

scripts/install.sh

@@ -4,7 +4,15 @@ umask 077
 
 REPO_URL=${MULTI_SIMADMIN_REPO_URL:-https://gitea.chickliu.fun/Hermes/multi-simadmin.git}
 PNPM_VERSION="11.13.0"
-APP_ROOT=${MULTI_SIMADMIN_HOME:-"$HOME/Library/Application Support/multi-simadmin"}
+PLATFORM=$(uname -s)
+default_app_root() {
+  case "$PLATFORM" in
+    Darwin) printf '%s' "$HOME/Library/Application Support/multi-simadmin" ;;
+    Linux) printf '%s' "${XDG_DATA_HOME:-$HOME/.local/share}/multi-simadmin" ;;
+    *) printf '' ;;
+  esac
+}
+APP_ROOT=${MULTI_SIMADMIN_HOME:-"$(default_app_root)"}
 SOURCE_DIR="$APP_ROOT/source"
 DATA_ROOT="$APP_ROOT/data"
 RUNTIME_DIR="$APP_ROOT/run"
@@ -29,14 +37,17 @@ Multi SimAdmin 一键安装与服务管理
   status     显示进程、端口与健康状态
   uninstall  卸载程序，默认保留数据、令牌和日志
 环境变量：
-  MULTI_SIMADMIN_HOME           安装根目录
+  MULTI_SIMADMIN_HOME           安装根目录（默认 macOS 为 ~/Library/Application Support/multi-simadmin，Linux 为 ~/.local/share/multi-simadmin）
   MULTI_SIMADMIN_ALLOWED_HOSTS  额外允许的 LAN 主机名/IP，逗号分隔
   MULTI_SIMADMIN_REPO_URL       源码仓库地址
 EOF
 }
 
-require_macos() {
-  [ "$(uname -s)" = Darwin ] || die "当前生产版仅支持 macOS（秘密存储依赖 macOS Keychain）。"
+require_platform() {
+  case "$PLATFORM" in
+    Darwin|Linux) ;;
+    *) die "当前生产版仅支持 macOS 或 Linux。" ;;
+  esac
 }
 
 require_commands() {
@@ -61,14 +72,27 @@ pid_owned() {
 }
 
 port_free() {
-  ! lsof -nP -iTCP:"$1" -sTCP:LISTEN >/dev/null 2>&1
+  if command -v lsof >/dev/null 2>&1; then
+    ! lsof -nP -iTCP:"$1" -sTCP:LISTEN >/dev/null 2>&1
+  elif command -v ss >/dev/null 2>&1; then
+    ! ss -ltn "( sport = :$1 )" 2>/dev/null | grep -q ":$1 "
+  else
+    die "缺少 lsof 或 ss，无法检查端口占用"
+  fi
 }
 
 lan_ip() {
-  for interface in en0 en1; do
-    value=$(ipconfig getifaddr "$interface" 2>/dev/null || true)
-    if [ -n "$value" ]; then printf '%s' "$value"; return; fi
-  done
+  if [ "$PLATFORM" = Darwin ]; then
+    for interface in en0 en1; do
+      value=$(ipconfig getifaddr "$interface" 2>/dev/null || true)
+      if [ -n "$value" ]; then printf '%s' "$value"; return; fi
+    done
+  else
+    value=$(ip -4 addr show scope global 2>/dev/null | awk '/inet /{print $2; exit}' | cut -d/ -f1)
+    if [ -n "${value:-}" ]; then printf '%s' "$value"; return; fi
+    value=$(hostname -I 2>/dev/null | awk '{print $1}')
+    if [ -n "${value:-}" ]; then printf '%s' "$value"; return; fi
+  fi
   printf '127.0.0.1'
 }
 
@@ -135,7 +159,7 @@ wait_for() {
 }
 
 start_service() {
-  require_macos
+  require_platform
   require_commands
   [ -f "$SOURCE_DIR/apps/web/dist/index.html" ] || die "尚未安装，请先运行 install"
   [ -f "$TOKEN_FILE" ] && [ ! -L "$TOKEN_FILE" ] || die "Gateway token 缺失或不是安全的普通文件，请重新运行 install"
@@ -192,6 +216,7 @@ start_service() {
   trap 'rollback_start' EXIT HUP INT TERM
   MULTI_SIMADMIN_DATA_ROOT="$DATA_ROOT" \
   MULTI_SIMADMIN_DATABASE_PATH="$DATA_ROOT/control-plane.sqlite3" \
+  MULTI_SIMADMIN_SECRET_BACKEND="$( [ "$PLATFORM" = Darwin ] && printf macos-keychain || printf secret-file )" \
   MULTI_SIMADMIN_GATEWAY_TOKEN="$token" \
   MULTI_SIMADMIN_WEB_DIST="$SOURCE_DIR/apps/web/dist" \
   API_HOST=127.0.0.1 API_PORT=8790 \
@@ -256,7 +281,7 @@ status_service() {
 }
 
 install_app() {
-  require_macos
+  require_platform
   require_commands
   mkdir -p "$APP_ROOT" "$DATA_ROOT" "$RUNTIME_DIR" "$LOG_DIR"
   chmod 700 "$APP_ROOT" "$DATA_ROOT" "$RUNTIME_DIR" "$LOG_DIR"