fix(tui): cursor position in the textarea

Hide the cursor when it's misaligned with the textarea.

internal/tui/tui.go

@@ -3,6 +3,7 @@ package tui
 import (
 	"context"
 	"fmt"
+	"strings"
 
 	"github.com/charmbracelet/bubbles/v2/key"
 	tea "github.com/charmbracelet/bubbletea/v2"
@@ -453,6 +454,11 @@ func (a *appModel) View() tea.View {
 	var cursor *tea.Cursor
 	if v, ok := page.(util.Cursor); ok {
 		cursor = v.Cursor()
+		// Hide the cursor if it's positioned outside the textarea
+		statusHeight := a.height - strings.Count(pageView, "\n") + 1
+		if cursor != nil && cursor.Y+statusHeight+chat.EditorHeight-2 <= a.height { // 2 for the top and bottom app padding
+			cursor = nil
+		}
 	}
 	activeView := a.dialog.ActiveModel()
 	if activeView != nil {