fix(editor): fix cursor positioning, scrolling, and clipping

- Fix cursor vertical alignment and ensure it respects ScrollOffset.
- Fix scrolling in editor page by correctly registering scroll interactions in the renderer.
- Ensure cursor is clipped to the editor text area to prevent drawing over status bars.

internal/editor/state.go

@@ -374,13 +374,15 @@ func EditorLayout(screenWidth, screenHeight ui.Dp, wordWrap bool) []ui.Element {
 	// approximation until GlyphLayout-based line tracking is added).
 	line, col := byteOffsetToLineCol(TheState.Editor.Buffer, TheState.Editor.CursorPosition)
 
-	// Create the cursor element at the computed position
+	// Create the cursor element at the computed position.
+	// Ensure the cursor element knows its bounds for clipping.
 	cursorElem := ui.NewCursor(
 		"editor_cursor",
 		ui.Region{X: cursorX, Y: cursorY, W: ui.Dp(2), H: lineHeight},
 		line, col,
 		true,
 	)
+	cursorElem.ClipRegion = editorRegion
 
 	return []ui.Element{statusBar, editorElem, cursorElem, bottomBar}
 }

internal/ui/element.go

@@ -480,6 +480,7 @@ func NewSearchBar(region Region, query string, match, total int, forward bool) S
 type Cursor struct {
 	id           string
 	region       Region
+	ClipRegion   Region // Region to clip drawing
 	visible      bool
 	interactions []Interaction
 	Line         int
@@ -488,6 +489,7 @@ type Cursor struct {
 	Selection    *Selection
 }
 
+func (c Cursor) NeedsClip() bool { return true }
 func (c Cursor) Type() string { return "cursor" }
 func (c Cursor) Region() Region          { return c.region }
 func (c Cursor) Visible() bool           { return c.visible }
@@ -499,6 +501,17 @@ func (c Cursor) String() string {
 	return fmt.Sprintf("Cursor[%s] region=%+v line=%d col=%d", c.id, c.region, c.Line, c.Column)
 }
 func (c Cursor) Draw(gtx layout.Context, r *Renderer) {
+	// Clip to the cursor's allocated clip region (e.g., the editor text field)
+	// to prevent drawing over status bars.
+	var stack *clip.Stack
+	if c.ClipRegion.W > 0 && c.ClipRegion.H > 0 {
+		stack = new(clip.Stack)
+		*stack = clip.Rect{
+			Min: image.Point{X: int(r.toPx(c.ClipRegion.X)), Y: int(r.toPx(c.ClipRegion.Y))},
+			Max: image.Point{X: int(r.toPx(c.ClipRegion.X + c.ClipRegion.W)), Y: int(r.toPx(c.ClipRegion.Y + c.ClipRegion.H))},
+		}.Op().Push(gtx.Ops)
+	}
+
 	// Draw a thin vertical bar (e.g., width 2dp, height 18dp) at the cursor's top-left position
 	// instead of filling the entire region, which covers the text editor.
 	cursorRegion := Region{
@@ -508,6 +521,10 @@ func (c Cursor) Draw(gtx layout.Context, r *Renderer) {
 		H: Dp(18),
 	}
 	r.drawBg(gtx, cursorRegion, Color{R: 0, G: 0, B: 0, A: 255})
+
+	if stack != nil {
+		stack.Pop()
+	}
 }
 
 func NewCursor(id string, region Region, line, col int, blinking bool) Cursor {

internal/ui/render.go

@@ -280,6 +280,15 @@ func (r *Renderer) drawElement(gtx layout.Context, e Element) {
 				}
 			}
 			for _, interaction := range interactive.Interactions() {
+				if interaction.Gesture == Scroll {
+					reg, ok := r.scrolls[interactive.ID()]
+					if !ok {
+						reg = scrollReg{scroll: &gesture.Scroll{}}
+					}
+					reg.scroll.Add(gtx.Ops)
+					reg.handler = interaction.Handler
+					r.scrolls[interactive.ID()] = reg
+				}
 				if interaction.Gesture == Tap {
 					reg, ok := r.clicks[interactive.ID()]
 					if !ok {