Merge nucleic/dapper-velvet-badger-dtr3 into dev

Sources/NucleicApp/ChatInputField.swift

@@ -266,6 +266,15 @@ struct ChatInputField: NSViewRepresentable {
 /// so the fitted height can be recomputed for the new text wrapping.
 final class HeightTrackingScrollView: NSScrollView {
     var onLayout: (() -> Void)?
+    /// `NSTextView` installs the I-beam directly when it handles a click. In a normal AppKit
+    /// hierarchy the next cursor rect under the pointer replaces it as soon as the pointer leaves,
+    /// but the SwiftUI views surrounding this representable do not consistently install an arrow
+    /// rect. That is especially visible in Home's tall, otherwise-empty hero field: the I-beam can
+    /// remain current across the whole window until AppKit's next cursor-rect rebuild.
+    ///
+    /// Track the scroll view rather than its document view so this covers the field's exact visible
+    /// bounds even when an empty `NSTextView` is shorter than the Home composer's minimum height.
+    private var cursorExitTrackingArea: NSTrackingArea?
 
     /// Force overlay-style scrollers, rejecting the system's legacy style ("Show scroll
     /// bars: Always", common with a mouse attached). A legacy scroller consumes layout
@@ -283,6 +292,25 @@ final class HeightTrackingScrollView: NSScrollView {
         set { _ = newValue; super.scrollerStyle = .overlay }
     }
 
+    override func updateTrackingAreas() {
+        super.updateTrackingAreas()
+        if let cursorExitTrackingArea { removeTrackingArea(cursorExitTrackingArea) }
+        let area = NSTrackingArea(
+            rect: .zero,
+            options: [.mouseEnteredAndExited, .activeInKeyWindow, .inVisibleRect],
+            owner: self,
+            userInfo: nil)
+        addTrackingArea(area)
+        cursorExitTrackingArea = area
+    }
+
+    override func mouseExited(with event: NSEvent) {
+        // `set()` is intentional: the text view also sets (rather than pushes) its cursor, so
+        // there is no balanced cursor-stack entry to pop here.
+        NSCursor.arrow.set()
+        super.mouseExited(with: event)
+    }
+
     override func layout() {
         super.layout()
         onLayout?()