Windows: verify EFI loader restoration

Verify restored EFI Microsoft and fallback boot loader paths after system decryption.

Show clearer recovery guidance when EFI file restoration or NVRAM cleanup remains incomplete.

Add a GPT-only EFI boot loader repair menu action for already decrypted systems.

src/Format/Tcformat.c

@@ -6677,6 +6677,7 @@ BOOL CALLBACK MainDialogProc (HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lPa
 								catch (Exception &e)
 								{
 									e.Show (hwndDlg);
+									return 1;
 								}
 
 								ManageStartupSeqWiz (TRUE, L"");
@@ -10782,4 +10783,4 @@ int WINAPI wWinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance, wchar_t *lpsz
 
 	return 0;
 }
-#endif
+#endif