feat: add pin/unpin functionality to chat history

Adds pin/unpin functionality to the chat history sidebar, allowing users to keep important conversations readily accessible. This improves user experience and helps organize past interactions.

This feature includes:
- Pin/unpin buttons in the chat history sidebar.
- Updated database schema to include `is_pinned` field for chat history items.
- Localized translations for pin/unpin actions.
- Updated UI to display pinned items at the top of the list.

src/components/Option/Knowledge/index.tsx

@@ -93,7 +93,7 @@ export const KnowledgeSettings = () => {
                 key: "action",
                 render: (text: string, record: any) => (
                   <div className="flex gap-4">
-                    <Tooltip title={t("tooltip.delete")}>
+                    <Tooltip title={t("common:delete")}>
                       <button
                         disabled={isDeleting}
                         onClick={() => {