A lot of interface stuff, some more cleanup and fixes. Main functionality should be mostly fine, importing works. Missing a lot of mod edit options.

Penumbra/Mods/Mod.BasePath.cs

@@ -0,0 +1,44 @@
+using System.IO;
+using Dalamud.Logging;
+
+namespace Penumbra.Mods;
+
+public enum ModPathChangeType
+{
+    Added,
+    Deleted,
+    Moved,
+}
+
+public partial class Mod
+{
+    public DirectoryInfo BasePath { get; private set; }
+    public int Index { get; private set; } = -1;
+
+    private Mod( DirectoryInfo basePath )
+        => BasePath = basePath;
+
+    public static Mod? LoadMod( DirectoryInfo basePath )
+    {
+        basePath.Refresh();
+        if( !basePath.Exists )
+        {
+            PluginLog.Error( $"Supplied mod directory {basePath} does not exist." );
+            return null;
+        }
+
+        var mod = new Mod( basePath );
+        mod.LoadMeta();
+        if( mod.Name.Length == 0 )
+        {
+            PluginLog.Error( $"Mod at {basePath} without name is not supported." );
+        }
+
+        mod.LoadDefaultOption();
+        mod.LoadAllGroups();
+        mod.ComputeChangedItems();
+        mod.SetCounts();
+
+        return mod;
+    }
+}