Temp limit TreeSitter to 6000 lines of code max.

* Hotfix to resolve issues with the syntax highlighter, which
  becomes unstable with very large files, need to dig into
  TreeSitter to find the culprit of this unstability before we
  can increase this threshold higher.

Sources/Kraken/IO/Universal/KIO.USD.swift

@@ -32,6 +32,12 @@ import UniformTypeIdentifiers
 
 public extension Kraken.IO
 {
+  /// temporary maximum number of characters (6000 lines * 90 wide)
+  /// for treesitter, since it becomes unstable with massive files
+  /// TODO: find the culprit in treesitter, and remove the maximum
+  /// threshold once fixed.
+  static let TREE_SITTER_MAX = 6000 * 90
+
   @Observable
   final class USD: ReferenceFileDocument
   {
@@ -75,15 +81,17 @@ public extension Kraken.IO
 
         var contents = ""
         context.stage.exportToString(&contents, addSourceFileComment: false)
-        context.usda = contents
+        context.usda = String(contents.prefix(Kraken.IO.TREE_SITTER_MAX))
         return
       }
-      context.usda = string
+      context.usda = String(string.prefix(Kraken.IO.TREE_SITTER_MAX))
     }
 
     public func fileWrapper(snapshot _: Kraken.IO.USD.Context, configuration _: WriteConfiguration) throws -> FileWrapper
     {
-      context.stage.exportToString(&context.usda, addSourceFileComment: false)
+      var contents = ""
+      context.stage.exportToString(&contents, addSourceFileComment: false)
+      context.usda = String(contents.prefix(Kraken.IO.TREE_SITTER_MAX))
 
       return .init(regularFileWithContents: context.usda.data(using: .utf8)!)
     }
@@ -122,7 +130,10 @@ public extension Kraken.IO.USD
       stage = Usd.Stage.open(fileURL.path)
 
       Kraken.IO.Stage.manager.save(&stage)
-      stage.exportToString(&usda, addSourceFileComment: false)
+
+      var contents = ""
+      stage.exportToString(&contents, addSourceFileComment: false)
+      usda = String(contents.prefix(Kraken.IO.TREE_SITTER_MAX))
     }
 
     public func open(fileURL: URL)
@@ -131,7 +142,10 @@ public extension Kraken.IO.USD
       stage = Usd.Stage.open(fileURL.path)
 
       Kraken.IO.Stage.manager.save(&stage)
-      stage.exportToString(&self.usda, addSourceFileComment: false)
+
+      var contents = ""
+      stage.exportToString(&contents, addSourceFileComment: false)
+      usda = String(contents.prefix(Kraken.IO.TREE_SITTER_MAX))
     }
   }
 }

Sources/Kraken/UI/Editors/KUI.CodeEditor.swift

@@ -100,14 +100,6 @@ public extension Kraken.UI
         Task
         {
           Kraken.IO.Stage.manager.reloadAndSave(stage: &C.context.stage)
-
-          var contents = ""
-          C.context.stage.exportToString(&contents, addSourceFileComment: false)
-
-          if C.context.usda != contents
-          {
-            C.context.usda = contents
-          }
         }
       }
       .onAppear