feat: add red-green 3D mode and Windows Forms GUI

- add rg (red-green) anaglyph subtitle mode with configurable horizontal offset
- extend CLI mode handling to support sbs, ou, and rg
- add offsetx option for anaglyph subtitle positioning
- add Windows Forms GUI project for configuring and running conversions
- add file pickers for input/output paths in the GUI
- add GUI controls for mode, resolution, font size, and offset
- add status output and mode-aware UI behavior in the GUI
- update mode selection handling to support user-friendly display labels

ConvertSRTto3DASSGUI/Properties/AssemblyInfo.cs

@@ -0,0 +1,33 @@
+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+// General Information about an assembly is controlled through the following
+// set of attributes. Change these attribute values to modify the information
+// associated with an assembly.
+[assembly: AssemblyTitle("ConvertSRTto3DASSGUI")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("Stanley Black & Decker inc.")]
+[assembly: AssemblyProduct("ConvertSRTto3DASSGUI")]
+[assembly: AssemblyCopyright("Copyright © Stanley Black & Decker inc. 2026")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+// Setting ComVisible to false makes the types in this assembly not visible
+// to COM components.  If you need to access a type in this assembly from
+// COM, set the ComVisible attribute to true on that type.
+[assembly: ComVisible(false)]
+
+// The following GUID is for the ID of the typelib if this project is exposed to COM
+[assembly: Guid("8c44f434-2097-4fa3-bee1-9569fb99f49c")]
+
+// Version information for an assembly consists of the following four values:
+//
+//      Major Version
+//      Minor Version
+//      Build Number
+//      Revision
+//
+[assembly: AssemblyVersion("1.0.0.0")]
+[assembly: AssemblyFileVersion("1.0.0.0")]