add eft install precheck

also updated wording of free space precheck when eft install isn't found

SPTInstaller/Installer Tasks/PreChecks/EftInstalledPreCheck.cs

@@ -0,0 +1,24 @@
+using System.Threading.Tasks;
+using SPTInstaller.Models;
+
+namespace SPTInstaller.Installer_Tasks.PreChecks;
+
+public class EftInstalledPreCheck : PreCheckBase
+{
+    private InternalData _internalData;
+    
+    public EftInstalledPreCheck(InternalData data) : base("EFT Installed", true)
+    {
+        _internalData = data;
+    }
+    
+    public override async Task<PreCheckResult> CheckOperation()
+    {
+        if (_internalData.OriginalGamePath is null || !Directory.Exists(_internalData.OriginalGamePath) || !File.Exists(Path.Join(_internalData.OriginalGamePath, "Escapefromtarkov.exe")))
+        {
+            return PreCheckResult.FromError("EFT installation could not be found", "Retry", RequestReevaluation);
+        }
+        
+        return PreCheckResult.FromSuccess("EFT install folder found");
+    }
+}

SPTInstaller/Installer Tasks/PreChecks/FreeSpacePreCheck.cs

@@ -33,7 +33,7 @@ public class FreeSpacePreCheck : PreCheckBase
             
             if (eftSourceDirSize == -1)
             {
-                return PreCheckResult.FromError("An error occurred while getting the EFT source directory size");
+                return PreCheckResult.FromError("An error occurred while getting the EFT source directory size. This is most likely because EFT is not installed");
             }
             
             var availableSize = DriveInfo.GetDrives()

SPTInstaller/Program.cs

@@ -44,6 +44,7 @@ internal class Program
         ServiceHelper.Register<InternalData>();
         
 #if !TEST
+        ServiceHelper.Register<PreCheckBase, EftInstalledPreCheck>();
         ServiceHelper.Register<PreCheckBase, NetFramework472PreCheck>();
         ServiceHelper.Register<PreCheckBase, Net8PreCheck>();
         ServiceHelper.Register<PreCheckBase, FreeSpacePreCheck>();