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-docs-routes.test.ts

@@ -0,0 +1,112 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+
+const mocks = vi.hoisted(() => ({
+  listKnowledgeDocs: vi.fn(),
+  uploadKnowledgeDoc: vi.fn(),
+  deleteKnowledgeDoc: vi.fn(),
+  isSafeKnowledgeDocName: vi.fn(),
+}));
+
+vi.mock('../electron/utils/knowledge-docs', () => ({
+  listKnowledgeDocs: mocks.listKnowledgeDocs,
+  uploadKnowledgeDoc: mocks.uploadKnowledgeDoc,
+  deleteKnowledgeDoc: mocks.deleteKnowledgeDoc,
+  isSafeKnowledgeDocName: mocks.isSafeKnowledgeDocName,
+}));
+
+import { normalizeRequest } from '../electron/api/route-utils';
+import { handleKnowledgeRoutes } from '../electron/api/routes/knowledge';
+
+const ctx = {
+  gatewayManager: null,
+  providerApiService: null,
+  mainWindow: null,
+} as any;
+
+describe('knowledge docs routes', () => {
+  beforeEach(() => {
+    mocks.listKnowledgeDocs.mockReset();
+    mocks.uploadKnowledgeDoc.mockReset();
+    mocks.deleteKnowledgeDoc.mockReset();
+    mocks.isSafeKnowledgeDocName.mockReset();
+    mocks.isSafeKnowledgeDocName.mockReturnValue(true);
+  });
+
+  it('returns listed knowledge docs from the local route', async () => {
+    mocks.listKnowledgeDocs.mockResolvedValue([
+      {
+        name: 'guide.md',
+        size: 128,
+        modifiedAt: '2026-04-18T10:00:00.000Z',
+        type: 'md',
+      },
+    ]);
+
+    const response = await handleKnowledgeRoutes(normalizeRequest({
+      path: '/api/knowledge/docs',
+      method: 'GET',
+    }), ctx);
+
+    expect(response?.ok).toBe(true);
+    expect(response?.json).toMatchObject({
+      success: true,
+      files: [
+        expect.objectContaining({
+          name: 'guide.md',
+          type: 'md',
+        }),
+      ],
+    });
+  });
+
+  it('uploads and deletes docs through the route contract', async () => {
+    mocks.uploadKnowledgeDoc.mockResolvedValue({
+      name: 'guide.md',
+      size: 128,
+      modifiedAt: '2026-04-18T10:00:00.000Z',
+      type: 'md',
+    });
+
+    const upload = await handleKnowledgeRoutes(normalizeRequest({
+      path: '/api/knowledge/docs',
+      method: 'POST',
+      body: JSON.stringify({
+        fileName: 'guide.md',
+        base64: Buffer.from('hello').toString('base64'),
+      }),
+    }), ctx);
+
+    expect(upload?.ok).toBe(true);
+    expect(upload?.json).toMatchObject({
+      success: true,
+      file: expect.objectContaining({
+        name: 'guide.md',
+      }),
+    });
+
+    const remove = await handleKnowledgeRoutes(normalizeRequest({
+      path: '/api/knowledge/docs/guide.md',
+      method: 'DELETE',
+    }), ctx);
+
+    expect(remove?.ok).toBe(true);
+    expect(remove?.json).toMatchObject({ success: true });
+    expect(mocks.deleteKnowledgeDoc).toHaveBeenCalledWith('guide.md');
+  });
+
+  it('rejects unsafe file names', async () => {
+    mocks.isSafeKnowledgeDocName.mockReturnValue(false);
+
+    const response = await handleKnowledgeRoutes(normalizeRequest({
+      path: '/api/knowledge/docs',
+      method: 'POST',
+      body: JSON.stringify({
+        fileName: '../escape.md',
+        base64: Buffer.from('bad').toString('base64'),
+      }),
+    }), ctx);
+
+    expect(response?.ok).toBe(false);
+    expect(response?.status).toBe(400);
+  });
+});