feat: replace ImMessageEditor with AgentMessageEditor and CustomerMessageEditor, refactor shared message editor logic

- Introduced AgentMessageEditor component for agent message handling.
- Created CustomerMessageEditor component to handle customer messages.
- Refactored shared message editor logic into SharedMessageEditor.
- Removed the old KefuMessageEditor component.
- Updated chat panel to use the new AgentMessageEditor.
- Updated KefuChatShell to use CustomerMessageEditor instead of KefuMessageEditor.
- Added quick reply fetching and handling in AgentMessageEditor.

web/components/kefu/customer-message-editor.tsx

@@ -0,0 +1,34 @@
+"use client"
+
+import {
+  SharedMessageEditor,
+  type UploadedMessageEditorImage,
+} from "@/components/chat/shared-message-editor"
+
+type CustomerMessageEditorProps = {
+  disabled?: boolean
+  uploadingAsset?: boolean
+  onSend: (html: string) => Promise<void>
+  onUploadImage: (file: File) => Promise<UploadedMessageEditorImage | null>
+  onSendAttachment: (file: File) => Promise<void>
+}
+
+export function CustomerMessageEditor({
+  disabled = false,
+  uploadingAsset = false,
+  onSend,
+  onUploadImage,
+  onSendAttachment,
+}: CustomerMessageEditorProps) {
+  return (
+    <SharedMessageEditor
+      variant="customer"
+      disabled={disabled}
+      uploadingAsset={uploadingAsset}
+      manageLocalUploading
+      onSend={onSend}
+      onUploadImage={onUploadImage}
+      onSendAttachment={onSendAttachment}
+    />
+  )
+}