Fix gutter rect width: always use container width (AppKit/UIKit)

Replace intersection-based max with containerView.frame.width to ensure full-
width gutter rendering and avoid clipped highlights.

Author: krzyzanowskim

Sources/STTextViewAppKit/STTextView+Gutter.swift

@@ -200,7 +200,7 @@ extension STTextView {
                             y: cellFrame.origin.y
                         ),
                         size: CGSize(
-                            width: max(cellFrame.intersection(gutterView.containerView.frame).width, gutterView.containerView.frame.width),
+                            width: gutterView.containerView.frame.width,
                             height: cellFrame.size.height
                         )
                     ).pixelAligned

Sources/STTextViewUIKit/STTextView+Gutter.swift

@@ -197,7 +197,7 @@ extension STTextView {
                             y: lineFragmentFrame.origin.y
                         ),
                         size: CGSize(
-                            width: max(lineFragmentFrame.intersection(gutterView.containerView.frame).width, gutterView.containerView.frame.width),
+                            width: gutterView.containerView.frame.width,
                             height: lineFragmentFrame.size.height
                         )
                     ).pixelAligned