feat: add comprehensive tests for token candidates and proxy log path metadata

- Implemented tests for the `/api/models/token-candidates` endpoint to verify model availability and token coverage scenarios.
- Added tests for `composeProxyLogMessage` to ensure proper formatting of log messages with downstream and upstream metadata.
- Created utility functions for parsing proxy log path metadata and handling missing token hints.
- Developed tests for the `Sites` and `TokenRoutes` components to validate UI behavior and interactions, including scrolling and group expansion.
- Introduced a custom hook `useAnimatedVisibility` for managing visibility animations in components.
- Enhanced the documentation link for site resources.

src/web/pages/sites.edit-scroll.test.tsx

@@ -0,0 +1,88 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+import { act, create, type ReactTestInstance } from 'react-test-renderer';
+import { MemoryRouter } from 'react-router-dom';
+import { ToastProvider } from '../components/Toast.js';
+import Sites from './Sites.js';
+
+const { apiMock } = vi.hoisted(() => ({
+  apiMock: {
+    getSites: vi.fn(),
+  },
+}));
+
+vi.mock('../api.js', () => ({
+  api: apiMock,
+}));
+
+function collectText(node: ReactTestInstance): string {
+  const children = node.children || [];
+  return children.map((child) => {
+    if (typeof child === 'string') return child;
+    return collectText(child);
+  }).join('');
+}
+
+async function flushMicrotasks() {
+  await act(async () => {
+    await Promise.resolve();
+    await Promise.resolve();
+  });
+}
+
+describe('Sites edit behavior', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  afterEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it('scrolls to page top when entering edit mode', async () => {
+    apiMock.getSites.mockResolvedValue([
+      {
+        id: 1,
+        name: 'Demo Site',
+        url: 'https://example.com',
+        platform: 'new-api',
+        status: 'active',
+      },
+    ]);
+
+    const scrollToMock = vi.fn();
+    Object.defineProperty(globalThis, 'scrollTo', {
+      configurable: true,
+      writable: true,
+      value: scrollToMock,
+    });
+
+    let root: ReturnType<typeof create> | null = null;
+    try {
+      await act(async () => {
+        root = create(
+          <MemoryRouter initialEntries={['/sites']}>
+            <ToastProvider>
+              <Sites />
+            </ToastProvider>
+          </MemoryRouter>,
+        );
+      });
+      await flushMicrotasks();
+
+      const editButton = root.root.find((node) => (
+        node.type === 'button'
+        && typeof node.props.onClick === 'function'
+        && collectText(node).trim() === '编辑'
+      ));
+
+      await act(async () => {
+        editButton.props.onClick();
+      });
+      await flushMicrotasks();
+
+      expect(scrollToMock).toHaveBeenCalledWith({ top: 0, behavior: 'smooth' });
+    } finally {
+      root?.unmount();
+    }
+  });
+});