feat: improve setup scripts

setup.ps1

@@ -543,8 +543,20 @@ function Configure-TTS {
     }
 }
 
+# Generate INTERNAL_KEY for worker-to-backend auth if not already present
+function Ensure-InternalKey {
+    $content = if (Test-Path $ENV_FILE) { Get-Content $ENV_FILE -Raw } else { "" }
+    if ($content -notmatch "(?m)^INTERNAL_KEY=") {
+        $bytes = New-Object byte[] 32
+        [System.Security.Cryptography.RandomNumberGenerator]::Fill($bytes)
+        $internal_key = ($bytes | ForEach-Object { $_.ToString("x2") }) -join ""
+        "INTERNAL_KEY=$internal_key" | Add-Content -Path $ENV_FILE -Encoding utf8
+    }
+}
+
 # Main advanced settings menu
 function Prompt-AdvancedSettings {
+    Ensure-InternalKey
     Write-Host ""
     $configure_advanced = Read-Host "Would you like to configure advanced settings? (y/N)"
     if ($configure_advanced -ne "y" -and $configure_advanced -ne "Y") {