refactor: update knowledge document types and API client interfaces

- Refactored types in `Knowledge/types.ts` to introduce new interfaces for document handling.
- Added `KnowledgeDocItem`, `KnowledgeDocsListResponse`, `KnowledgeDocsUploadInput`, `KnowledgeDocsUploadResponse`, and `KnowledgeDocsDeleteResponse` for better structure and clarity.
- Updated `KnowledgeDocsApiClient` interface to include methods for listing, uploading, and deleting documents.

fix: replace deprecated icons in AccountSettingsPanel and SettingMenu

- Replaced `CheckCircleIcon` with `CheckCircle` from `lucide-react` in `AccountSettingsPanel.tsx`.
- Updated `SettingMenu.tsx` to use `Settings` and `User` from `lucide-react` instead of custom icons.

test: add tests for knowledge docs routes and KnowledgePage

- Created `knowledge-docs-routes.test.ts` to test API routes for listing, uploading, and deleting knowledge documents.
- Added `knowledge-page.test.tsx` to test the rendering and functionality of the KnowledgePage component, including document loading and deletion.

src/pages/Knowledge/components/KnowledgePageHeader.tsx

@@ -0,0 +1,42 @@
+export type KnowledgePageHeaderProps = {
+  title: string;
+  subtitle: string;
+  totalCount: number;
+  totalSize: string;
+  documentsLabel: string;
+  storageLabel: string;
+};
+
+export default function KnowledgePageHeader({
+  title,
+  subtitle,
+  totalCount,
+  totalSize,
+  documentsLabel,
+  storageLabel,
+}: KnowledgePageHeaderProps) {
+  return (
+    <div className="mb-6 flex shrink-0 flex-col justify-between gap-4 md:flex-row md:items-start">
+      <div>
+        <h1
+          className="mb-3 text-5xl font-normal tracking-tight text-[#171717] dark:text-[#f3f4f6] md:text-6xl"
+          style={{ fontFamily: "Georgia, Cambria, 'Times New Roman', Times, serif" }}
+        >
+          {title}
+        </h1>
+        <p className="text-[17px] font-medium text-[#171717]/70 dark:text-gray-400">{subtitle}</p>
+      </div>
+
+      <div className="grid gap-3 sm:grid-cols-2 md:mt-2 md:min-w-[320px]">
+        <div className="rounded-[24px] bg-[#f4f7fb] px-5 py-4 dark:bg-[#222225]">
+          <div className="text-xs uppercase tracking-[0.18em] text-[#99A0AE] dark:text-gray-500">{documentsLabel}</div>
+          <div className="mt-3 text-3xl font-semibold text-[#171717] dark:text-[#f3f4f6]">{totalCount}</div>
+        </div>
+        <div className="rounded-[24px] bg-[#fff7ed] px-5 py-4 dark:bg-[#31251a]">
+          <div className="text-xs uppercase tracking-[0.18em] text-[#6b7280] dark:text-gray-400">{storageLabel}</div>
+          <div className="mt-3 text-3xl font-semibold text-[#171717] dark:text-[#f3f4f6]">{totalSize}</div>
+        </div>
+      </div>
+    </div>
+  );
+}