fix(diff): remove unused imports in DiffLangSketch

Clean up the code by removing unused imports related to diff handling and UI components in DiffLangSketch.kt.

Author: phodal

core/src/main/kotlin/cc/unitmesh/devti/sketch/ui/patch/DiffLangSketch.kt

@@ -2,9 +2,6 @@ package cc.unitmesh.devti.sketch.ui.patch
 
 import cc.unitmesh.devti.AutoDevBundle
 import cc.unitmesh.devti.AutoDevNotifications
-import cc.unitmesh.devti.diff.DiffStreamHandler
-import cc.unitmesh.devti.diff.DiffStreamService
-import cc.unitmesh.devti.diff.model.streamDiff
 import cc.unitmesh.devti.sketch.ui.ExtensionLangSketch
 import cc.unitmesh.devti.util.findFile
 import com.intellij.icons.AllIcons
@@ -15,8 +12,6 @@ import com.intellij.openapi.command.UndoConfirmationPolicy
 import com.intellij.openapi.command.undo.UndoManager
 import com.intellij.openapi.diff.impl.patch.PatchReader
 import com.intellij.openapi.diff.impl.patch.TextFilePatch
-import com.intellij.openapi.diff.impl.patch.apply.GenericPatchApplier
-import com.intellij.openapi.fileEditor.FileDocumentManager
 import com.intellij.openapi.fileEditor.FileEditorManager
 import com.intellij.openapi.fileEditor.FileEditorProvider
 import com.intellij.openapi.project.Project
@@ -27,12 +22,9 @@ import com.intellij.openapi.vcs.changes.patch.MatchPatchPaths
 import com.intellij.openapi.vfs.VirtualFile
 import com.intellij.psi.PsiDocumentManager
 import com.intellij.testFramework.LightVirtualFile
-import com.intellij.ui.JBColor
 import com.intellij.ui.components.panels.VerticalLayout
 import com.intellij.util.containers.MultiMap
 import com.intellij.util.ui.JBUI
-import git4idea.changes.filePath
-import kotlinx.coroutines.flow.flowOf
 import java.awt.BorderLayout
 import javax.swing.BoxLayout
 import javax.swing.JButton