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.

tests/knowledge-page.test.tsx

@@ -0,0 +1,95 @@
+import React from 'react';
+import { fireEvent, render, screen, waitFor } from '@testing-library/react';
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+
+const apiMocks = vi.hoisted(() => ({
+  list: vi.fn(),
+  upload: vi.fn(),
+  delete: vi.fn(),
+}));
+
+vi.mock('../src/lib/knowledge-docs-api', () => ({
+  knowledgeDocsApi: apiMocks,
+}));
+
+vi.mock('../src/pages/Knowledge/copy', () => ({
+  useKnowledgeCopy: () => (path: string, params?: Record<string, string>, fallback?: string) => {
+    const dictionary: Record<string, string> = {
+      'knowledge.title': 'Knowledge Docs',
+      'knowledge.subtitle': 'Manage docs',
+      'knowledge.documentsLabel': 'Documents',
+      'knowledge.storageLabel': 'Storage',
+      'knowledge.refresh': 'Refresh',
+      'knowledge.upload': 'Upload',
+      'knowledge.uploadHint': 'Knowledge docs only',
+      'knowledge.status.loading': 'Loading documents...',
+      'knowledge.status.uploading': 'Uploading...',
+      'knowledge.status.deleting': 'Deleting...',
+      'knowledge.status.uploadSuccess': 'Uploaded',
+      'knowledge.status.deleteSuccess': 'Deleted',
+      'knowledge.emptyTitle': 'No documents yet',
+      'knowledge.emptyDescription': 'Upload a file',
+      'knowledge.deleteConfirm': 'Delete this document?',
+      'knowledge.table.name': 'Name',
+      'knowledge.table.size': 'Size',
+      'knowledge.table.modifiedAt': 'Modified At',
+      'knowledge.table.type': 'Type',
+      'knowledge.table.actions': 'Actions',
+      'knowledge.table.delete': 'Delete',
+    };
+
+    if (path === 'knowledge.status.failed') {
+      return `Knowledge docs request failed: ${params?.error ?? ''}`;
+    }
+
+    return dictionary[path] ?? fallback ?? path;
+  },
+}));
+
+import KnowledgePage from '../src/pages/Knowledge';
+
+describe('KnowledgePage', () => {
+  beforeEach(() => {
+    apiMocks.list.mockReset();
+    apiMocks.upload.mockReset();
+    apiMocks.delete.mockReset();
+    vi.stubGlobal('confirm', vi.fn(() => true));
+  });
+
+  it('loads and renders docs from the knowledge docs api', async () => {
+    apiMocks.list.mockResolvedValue([
+      {
+        name: 'guide.md',
+        size: 1024,
+        modifiedAt: '2026-04-18T10:00:00.000Z',
+        type: 'md',
+      },
+    ]);
+
+    render(<KnowledgePage />);
+
+    expect(await screen.findByText('guide.md')).toBeTruthy();
+    expect(screen.getByText('MD')).toBeTruthy();
+  });
+
+  it('deletes a doc after confirmation', async () => {
+    apiMocks.list.mockResolvedValue([
+      {
+        name: 'guide.md',
+        size: 1024,
+        modifiedAt: '2026-04-18T10:00:00.000Z',
+        type: 'md',
+      },
+    ]);
+    apiMocks.delete.mockResolvedValue(undefined);
+
+    render(<KnowledgePage />);
+
+    const deleteButton = await screen.findByRole('button', { name: /delete/i });
+    fireEvent.click(deleteButton);
+
+    await waitFor(() => {
+      expect(apiMocks.delete).toHaveBeenCalledWith('guide.md');
+    });
+  });
+});