feat(migration): add Migrate-To-V2.ps1 idempotent migration runner

scripts/migration/Migrate-To-V2.ps1

@@ -0,0 +1,59 @@
+<#
+.SYNOPSIS
+    Idempotent migration runner that takes the OtOpcUaConfig database from the v1 schema
+    (with ConfigGeneration / ClusterNodeGenerationState) to the v2 hosting-aligned schema
+    (with Deployment / NodeDeploymentState / ConfigEdit / DataProtectionKeys).
+
+.DESCRIPTION
+    Backs the database up, applies the idempotent EF migration script, then validates that
+    expected tables exist and legacy tables are gone. Safe to re-run — the EF script itself
+    is idempotent, and the backup picks a unique filename per invocation.
+
+.PARAMETER ConnectionString
+    Mandatory. Full ADO.NET connection string with permissions to BACKUP DATABASE and
+    apply DDL on the target ConfigDb.
+
+.PARAMETER BackupPath
+    Optional. Full path for the backup file. Defaults to a timestamped path under $env:TEMP.
+
+.EXAMPLE
+    .\Migrate-To-V2.ps1 -ConnectionString "Server=sql01;Database=OtOpcUaConfig;Trusted_Connection=True;TrustServerCertificate=True"
+#>
+[CmdletBinding()]
+param(
+    [Parameter(Mandatory)][string] $ConnectionString,
+    [string] $BackupPath = "$env:TEMP\OtOpcUa-V1-Backup-$(Get-Date -Format yyyyMMddHHmmss).bak"
+)
+
+$ErrorActionPreference = 'Stop'
+
+if (-not (Get-Command Invoke-Sqlcmd -ErrorAction SilentlyContinue)) {
+    throw "Invoke-Sqlcmd not available. Install module: Install-Module SqlServer -Scope CurrentUser"
+}
+
+Write-Host "Step 1/4 — Backup ConfigDb to $BackupPath" -ForegroundColor Cyan
+Invoke-Sqlcmd -ConnectionString $ConnectionString `
+    -Query "BACKUP DATABASE [OtOpcUaConfig] TO DISK = '$BackupPath' WITH FORMAT, COMPRESSION"
+
+Write-Host "Step 2/4 — Row counts (before)" -ForegroundColor Cyan
+$beforeCounts = Invoke-Sqlcmd -ConnectionString $ConnectionString -InputFile "$PSScriptRoot\count-rows.sql"
+$beforeCounts | Format-Table
+
+Write-Host "Step 3/4 — Apply Migrate-To-V2.sql" -ForegroundColor Cyan
+Invoke-Sqlcmd -ConnectionString $ConnectionString -InputFile "$PSScriptRoot\Migrate-To-V2.sql" -QueryTimeout 1800
+
+Write-Host "Step 4/4 — Row counts (after) + validation" -ForegroundColor Cyan
+$afterCounts = Invoke-Sqlcmd -ConnectionString $ConnectionString -InputFile "$PSScriptRoot\count-rows.sql"
+$afterCounts | Format-Table
+
+$tablesNow = (Invoke-Sqlcmd -ConnectionString $ConnectionString `
+    -Query "SELECT name FROM sys.tables ORDER BY name").name
+
+foreach ($t in 'Deployment','NodeDeploymentState','ConfigEdit','DataProtectionKeys') {
+    if ($tablesNow -notcontains $t) { throw "Expected v2 table $t missing." }
+}
+foreach ($t in 'ConfigGeneration','ClusterNodeGenerationState') {
+    if ($tablesNow -contains $t) { throw "Legacy v1 table $t still present." }
+}
+
+Write-Host "Migration complete. Backup at $BackupPath" -ForegroundColor Green