fix: WinRM RDP update PowerShell quoting via EncodedCommand (0.20.10)

Broken -Command quotes caused ParserError on remote hosts; run deploy script through base64-encoded PowerShell.

backend/tests/test_winrm_connect.py

@@ -0,0 +1,33 @@
+"""WinRM command builder tests."""
+
+import base64
+
+from app.services.winrm_connect import _winrm_rdp_update_remote_cmd
+
+
+def test_rdp_update_default_uses_encoded_command_without_broken_quotes():
+    cmd = _winrm_rdp_update_remote_cmd("")
+    assert "-EncodedCommand" in cmd
+    assert "-Command" not in cmd
+    assert '"& {' not in cmd
+
+    encoded = cmd.rsplit(" ", 1)[-1]
+    script = base64.b64decode(encoded).decode("utf-16-le")
+    assert "Deploy-LoginMonitor.ps1" in script
+    assert "Join-Path $env:ProgramData" in script
+
+
+def test_rdp_update_custom_script_uses_encoded_command():
+    cmd = _winrm_rdp_update_remote_cmd(r"C:\ProgramData\LoginMonitor\Deploy-LoginMonitor.ps1")
+    assert "-EncodedCommand" in cmd
+    encoded = cmd.rsplit(" ", 1)[-1]
+    script = base64.b64decode(encoded).decode("utf-16-le")
+    assert r"C:\ProgramData\LoginMonitor\Deploy-LoginMonitor.ps1" in script
+    assert "Test-Path -LiteralPath" in script
+
+
+def test_rdp_update_custom_script_escapes_single_quotes():
+    cmd = _winrm_rdp_update_remote_cmd(r"C:\Users\O'Brien\Deploy-LoginMonitor.ps1")
+    encoded = cmd.rsplit(" ", 1)[-1]
+    script = base64.b64decode(encoded).decode("utf-16-le")
+    assert "O''Brien" in script