fix: audit hardening 2.1.10-SAC — gitignore, SAC TLS warn, Exchange safety

- Extend .gitignore for local settings, logs, spool, backups
- Log CRITICAL when SacTlsSkipVerify is enabled (Login_Monitor + Sac-Client)
- Exchange-MailSecurity: -WhatIf dry-run, scan safety warnings, v1.6.8
- Remove legacy Watchdog_RDP_Monitor.ps1 and Install-ScheduledTasks.ps1
- Add scripts for GitHub sanitize mirror push workflow

Sac-Client.ps1

@@ -1,4 +1,4 @@
-<#
+<#
 .SYNOPSIS
     Клиент Security Alert Center для RDP-login-monitor.
 .DESCRIPTION
@@ -420,6 +420,7 @@ function Test-SacShouldAttemptSend {
 function Invoke-SacTlsPrep {
     if (-not $SacTlsSkipVerify) { return }
     if (-not $script:SacTlsCallbackRegistered) {
+        Write-SacLog 'CRITICAL: SacTlsSkipVerify=$true — TLS certificate validation disabled for SAC (MITM risk). Use only for short-lived lab debugging.'
         [System.Net.ServicePointManager]::ServerCertificateValidationCallback = { $true }
         $script:SacTlsCallbackRegistered = $true
     }