refactor(devti): adjust task panel padding and visibility logic #352

- Reduce right padding from 16 to 0 in TaskSectionPanel border
- Increase left padding from 4 to 8 in stepsPanel border
- Simplify steps visibility toggle by removing redundant revalidate/repaint calls
- Remove unused CompoundBorder import in TaskStepPanel

Author: phodal

core/src/main/kotlin/cc/unitmesh/devti/sketch/ui/plan/TaskSectionPanel.kt

@@ -42,15 +42,15 @@ class TaskSectionPanel(
         background = JBUI.CurrentTheme.ToolWindow.background()
         border = CompoundBorder(
             BorderFactory.createMatteBorder(0, 0, 1, 0, JBColor.border()),
-            JBUI.Borders.empty(4, 16)
+            JBUI.Borders.empty(4, 0)
         )
 
         val headerPanel = createHeaderPanel()
         add(headerPanel, BorderLayout.NORTH)
 
         stepsPanel.layout = BoxLayout(stepsPanel, BoxLayout.Y_AXIS)
         stepsPanel.background = JBUI.CurrentTheme.ToolWindow.background()
-        stepsPanel.border = JBUI.Borders.emptyLeft(4)
+        stepsPanel.border = JBUI.Borders.emptyLeft(8)
 
         refreshStepsPanel()
 
@@ -158,15 +158,11 @@ class TaskSectionPanel(
 
     private fun toggleStepsVisibility(visible: Boolean) {
         scrollPane.isVisible = visible
-        SwingUtilities.invokeLater {
-            parent?.revalidate()
-            parent?.repaint()
-        }
+        stepsPanel.isVisible = visible
     }
 
     private fun refreshStepsPanel() {
         stepsPanel.removeAll()
-
         planItem.steps.forEach { step ->
             val taskStepPanel = TaskStepPanel(project, step) {
                 updateSectionStatus()

core/src/main/kotlin/cc/unitmesh/devti/sketch/ui/plan/TaskStepPanel.kt

@@ -23,7 +23,6 @@ import java.awt.Font
 import java.awt.event.MouseAdapter
 import java.awt.event.MouseEvent
 import javax.swing.*
-import javax.swing.border.CompoundBorder
 import javax.swing.text.AttributeSet
 import javax.swing.text.SimpleAttributeSet
 import javax.swing.text.StyleConstants