fix(tools): start_mcp_server 健壮性(.env -PathType Leaf + LASTEXITCODE 检查)

CodeRabbit 增量 review 2 条:
- .env 用 Test-Path -PathType Leaf(排除 .env 是目录的边界,目录会让 uv 失败)。
- cmd /c 后检查 $LASTEXITCODE 非零则 exit(ErrorActionPreference 对原生命令无效,非零退出码不进 catch,否则启动失败仍报成功)。

Co-Authored-By: Claude Code <noreply@anthropic.com>
Co-Authored-By: glm-5.2 <noreply@bigmodel.cn>

Author: 3 people

tools/mcp/start_mcp_server.ps1

@@ -41,12 +41,17 @@ Write-Host ""
 # Switch to project root
 Set-Location $ProjectRoot
 
-# --env-file 仅在 .env 存在时传(缺失时 uv 会在启动前失败,导致开机自启起不来)
-$EnvArg = if (Test-Path ".env") { "--env-file .env" } else { "" }
+# --env-file 仅在 .env 是普通文件时传(目录或缺失都不传;缺失时 uv 启动失败导致自启起不来)
+$EnvArg = if (Test-Path ".env" -PathType Leaf) { "--env-file .env" } else { "" }
 try {
     # Redirect via cmd /c: merge stdout/stderr into one file as raw bytes (matches
     # daemon subprocess.Popen(stdout=file, stderr=STDOUT); avoids PS native-redirect encoding issues)
     cmd /c "uv run $EnvArg python -m zzz_od.backend.entry.server --host $HostName --port $Port > `"$LogPath`" 2>&1"
+    # cmd /c 的非零退出码不会触发 catch(ErrorActionPreference 对原生命令无效),手动检查避免启动失败仍报成功
+    if ($LASTEXITCODE -ne 0) {
+        Write-Host "[ERROR] Main MCP Server exited with code $LASTEXITCODE" -ForegroundColor Red
+        exit $LASTEXITCODE
+    }
 } catch {
     Write-Host "[ERROR] Main MCP Server failed to start: $_" -ForegroundColor Red
     exit 1