fix(windows): use pkgs stable 'latest' installer to avoid 404

GitHub의 releases/latest 태그(예: 1.98.3)와 pkgs.tailscale.com/stable
채널 버전(예: 1.98.4)이 어긋나면 tailscale-setup-<버전>.exe URL이 404가
난다. 버전 조립을 없애고 항상 존재하는 tailscale-setup-latest.exe를 사용.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

farmq-install-en.ps1

@@ -110,22 +110,14 @@ function Install-Tailscale {
     }
     
     Write-Info "Installing Tailscale for Windows..."
-    
-    # Get latest Tailscale version
-    try {
-        Write-Status "Getting latest Tailscale version..."
-        $latestRelease = Invoke-RestMethod -Uri "https://api.github.com/repos/tailscale/tailscale/releases/latest" -UseBasicParsing
-        $version = $latestRelease.tag_name.TrimStart('v')
-        Write-Info "Latest version: $version"
-    }
-    catch {
-        Write-Warning "Failed to get latest version, using fallback"
-        $version = "1.86.2"
-    }
-    
-    # Temporary download path
-    $tempPath = "$env:TEMP\tailscale-setup-$version.exe"
-    $downloadUrl = "https://pkgs.tailscale.com/stable/tailscale-setup-$version.exe"
+
+    # Always use the 'latest' installer from the official stable channel.
+    # NOTE: GitHub's "latest release" tag and pkgs.tailscale.com/stable can be out
+    # of sync (e.g. GitHub reports 1.98.3 while stable already serves 1.98.4), so
+    # building a versioned URL such as tailscale-setup-<version>.exe results in a
+    # 404. The 'latest' alias always exists, so we use it directly.
+    $downloadUrl = "https://pkgs.tailscale.com/stable/tailscale-setup-latest.exe"
+    $tempPath = "$env:TEMP\tailscale-setup-latest.exe"
     
     try {
         Write-Status "Downloading Tailscale from: $downloadUrl"