feat(deploy): 补齐凭据加密接入迁移和密钥备份恢复

首次安装默认生成独立加密密钥，更新旧部署保留原配置，通过显式开关进入迁移窗口。增加生产迁移包装入口和完整密钥环备份恢复工具，并说明旧镜像升级、严格迁移、轮换及还原流程。

已通过 Bash 安全环境及密钥备份回归；对应 PowerShell 5.1 和 7 脚本已在 Windows 原生环境各通过 49 项验收。宁波服务器验收尚未执行。

scripts/Migrate-CredentialEncryption.ps1

@@ -0,0 +1,28 @@
+#Requires -Version 5.1
+param(
+    [ValidateSet('inventory','dry-run','apply','verify','finalize')][string]$Mode = 'inventory',
+    [Parameter(Mandatory=$true)][string]$ExpectedTarget
+)
+$ErrorActionPreference = 'Stop'
+$root = Split-Path -Parent (Split-Path -Parent $MyInvocation.MyCommand.Path)
+Set-Location $root
+. (Join-Path $root 'scripts/Initialize-SecurityEnv.ps1')
+Initialize-SecurityEnv -Path (Join-Path $root '.env') -Mode upgrade
+$content = Get-Content (Join-Path $root '.env') -Raw
+if (-not (Get-EnvValue $content 'CONFIG_CREDENTIAL_ENCRYPTION_KEYRING')) { throw 'Configure independent encryption keys and prepare database/queue backup before migrating' }
+$checkpointDir = Join-Path $root 'data/credential-migration'
+[System.IO.Directory]::CreateDirectory($checkpointDir) | Out-Null
+if ($env:OS -eq 'Windows_NT') {
+    $identity = [System.Security.Principal.WindowsIdentity]::GetCurrent().User
+    $acl = New-Object System.Security.AccessControl.DirectorySecurity
+    $acl.SetAccessRuleProtection($true, $false)
+    $rule = New-Object System.Security.AccessControl.FileSystemAccessRule($identity, 'FullControl', 'ContainerInherit,ObjectInherit', 'None', 'Allow')
+    $acl.AddAccessRule($rule)
+    Set-Acl -LiteralPath $checkpointDir -AclObject $acl
+}
+$toolArgs = @("--mode=$Mode", '--production=true', "--expected-target=$ExpectedTarget", '--batch-size=100', '--checkpoint=/credential-migration/checkpoint.json')
+if ($Mode -eq 'finalize') { $toolArgs = @('--mode=verify', '--finalize=true', '--production=true', "--expected-target=$ExpectedTarget", '--batch-size=100') }
+docker compose version *> $null
+if ($LASTEXITCODE -eq 0) { docker compose run --rm --no-deps -v "${checkpointDir}:/credential-migration" easyai-server node /app/dist/credential-migrate.js @toolArgs }
+else { docker-compose run --rm --no-deps -v "${checkpointDir}:/credential-migration" easyai-server node /app/dist/credential-migrate.js @toolArgs }
+if ($LASTEXITCODE -ne 0) { throw 'Credential migration failed; preserve checkpoint and resolve configuration or concurrency conflicts' }