fix: 移除 BOM 并增强 UTF-8 编码修复

- 移除 UTF-8 BOM (BOM 会破坏 iwr|iex 管道导致 param() 报错)
- 去掉 $Host.Name 守卫，无条件设置 Console 编码 (try/catch 兜底)
- chcp 65001 先于 Console.OutputEncoding 设置，确保代码页一致

GeminiCLI/setup-gemini.ps1

@@ -1,4 +1,4 @@
-# Gemini CLI Configuration Script for XCodeCLI (Windows)
+# Gemini CLI Configuration Script for XCodeCLI (Windows)
 # This script configures Gemini CLI to use your XCodeCLI instance
 # Automatically tests multiple API endpoints and selects the working one
 # Run with: powershell -ExecutionPolicy Bypass -File setup-gemini.ps1 -ApiKey YOUR_KEY
@@ -17,14 +17,12 @@ if (-not $ApiKey -and (Test-Path Variable:key)) { $ApiKey = $key }
 # 确保中文字符在各种 PowerShell 环境中正确显示
 # 兼容: Windows PowerShell 5.x, PowerShell 7.x, Windows Terminal, conhost, ISE, iwr|iex
 try {
-    if ($Host.Name -eq 'ConsoleHost') {
-        [Console]::OutputEncoding = [System.Text.Encoding]::UTF8
-        [Console]::InputEncoding = [System.Text.Encoding]::UTF8
-    }
-    $OutputEncoding = [System.Text.Encoding]::UTF8
     if ($env:OS -eq 'Windows_NT') {
         & cmd /c "chcp 65001 >nul" 2>&1 | Out-Null
     }
+    [Console]::OutputEncoding = [System.Text.Encoding]::UTF8
+    [Console]::InputEncoding = [System.Text.Encoding]::UTF8
+    $OutputEncoding = [System.Text.Encoding]::UTF8
 } catch { }
 
 # Configuration