feat(installer): add -version flag to pin 3x-ui release

Accepts 3.4.2 or v3.4.2; validates the tag exists on GitHub before
download, falls back to latest when omitted.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

CLAUDE.md

@@ -27,7 +27,7 @@ effect on servers only after push to `main`.
 ## What x-ui-latest.sh does
 
 1. Checks OS (Ubuntu 24.04/26.04, Debian 12/13) and rejects QEMU-emulated CPUs
-2. Parses CLI arguments (`-install y`, `-subdomain`, `-reality_domain`, `-auto_domain y`, `-uninstall y`)
+2. Parses CLI arguments (`-install y`, `-subdomain`, `-reality_domain`, `-auto_domain y`, `-version <ver>`, `-uninstall y`)
 3. Validates domains (panel ≠ REALITY), then stops/cleans any previous install
 4. Installs packages (`install_packages`) — nginx-full, certbot, sqlite3, ufw, mtr, python3 …
 5. Obtains Let's Encrypt certs via certbot standalone (`get_ssl_certs`) — panel + reality domains

README.md

@@ -88,6 +88,7 @@ bash x-ui-latest.sh -uninstall y
 | `-subdomain <домен>` | Домен панели и подписок |
 | `-reality_domain <домен>` | Домен назначения для REALITY |
 | `-auto_domain y` | Автоопределение домена (без ручного ввода) |
+| `-version <версия>` | Установить конкретную версию 3x-ui (например `3.4.2`), по умолчанию — последняя |
 | `-uninstall y` | Полное удаление |
 
 ---

README_EN.md

@@ -88,6 +88,7 @@ bash x-ui-latest.sh -uninstall y
 | `-subdomain <domain>` | Panel and subscription domain |
 | `-reality_domain <domain>` | REALITY destination domain |
 | `-auto_domain y` | Auto-detect domain (no manual input) |
+| `-version <version>` | Install specific 3x-ui version (e.g. `3.4.2`), default — latest |
 | `-uninstall y` | Full uninstall |
 
 ---

x-ui-latest.sh

@@ -126,6 +126,7 @@ while [ "$#" -gt 0 ]; do
         -subdomain)        domain="$2";            shift 2 ;;
         -reality_domain)   reality_domain="$2";    shift 2 ;;
         -ONLY_CF_IP_ALLOW) CFALLOW="$2";           shift 2 ;;
+        -version)          PANEL_VERSION="$2";     shift 2 ;;
         -uninstall)        UNINSTALL="$2";         shift 2 ;;
         *)                 shift 1 ;;
     esac
@@ -727,6 +728,13 @@ install_panel() {
 
     cd /usr/local/
 
+    if [[ -n "$PANEL_VERSION" ]]; then
+        tag_version="v${PANEL_VERSION#v}"
+        if ! curl -fsLo /dev/null "https://api.github.com/repos/MHSanaei/3x-ui/releases/tags/${tag_version}" \
+           && ! curl -4 -fsLo /dev/null "https://api.github.com/repos/MHSanaei/3x-ui/releases/tags/${tag_version}"; then
+            echo "3x-ui release ${tag_version} not found." && exit 1
+        fi
+    else
         tag_version=$(curl -Ls "https://api.github.com/repos/MHSanaei/3x-ui/releases/latest" \
             | grep '"tag_name":' | sed -E 's/.*"([^"]+)".*/\1/')
         if [[ -z "$tag_version" ]]; then
@@ -736,6 +744,7 @@ install_panel() {
         if [[ -z "$tag_version" ]]; then
             echo "Failed to fetch 3x-ui version." && exit 1
         fi
+    fi
 
     echo "Installing 3x-ui ${tag_version} ..."
     wget -N -O /usr/local/x-ui-linux-$(_arch).tar.gz \