feat: unify plugin workspace navigation

tests/unit/plugin-navigation.test.tsx

@@ -0,0 +1,43 @@
+import { fireEvent, render, screen } from '@testing-library/react';
+import { MemoryRouter, Route, Routes, useLocation, useNavigate } from 'react-router-dom';
+import { describe, expect, it } from 'vitest';
+import { LegacyPluginRedirect } from '@/pages/Plugins/legacy-plugin-redirect';
+import { getGuardedAiModuleForPath, isProgrammingProviderRoute } from '@/lib/ai-modules';
+
+function LocationProbe() {
+  const location = useLocation();
+  const navigate = useNavigate();
+  return (
+    <div>
+      <output data-testid="location">{location.pathname}{location.search}</output>
+      <button type="button" onClick={() => navigate(-1)}>返回</button>
+    </div>
+  );
+}
+
+describe('plugin navigation cutover', () => {
+  it.each([
+    ['/plugin-marketplace', '/plugins?scope=all&source=official'],
+    ['/my-plugins', '/plugins?scope=all&state=mine'],
+    ['/project-plugins', '/plugins?scope=project'],
+  ] as const)('replace-redirects %s to %s', async (legacy, canonical) => {
+    render(
+      <MemoryRouter initialEntries={['/previous', legacy]} initialIndex={1}>
+        <Routes>
+          <Route path={legacy} element={<LegacyPluginRedirect from={legacy} />} />
+          <Route path="/plugins" element={<LocationProbe />} />
+          <Route path="/previous" element={<output data-testid="previous">previous</output>} />
+        </Routes>
+      </MemoryRouter>,
+    );
+
+    expect(await screen.findByTestId('location')).toHaveTextContent(canonical);
+    fireEvent.click(screen.getByRole('button', { name: '返回' }));
+    expect(await screen.findByTestId('previous')).toBeVisible();
+  });
+
+  it('classifies the canonical page as Code without making it provider-gated', () => {
+    expect(getGuardedAiModuleForPath('/plugins')).toBe('programming');
+    expect(isProgrammingProviderRoute('/plugins')).toBe(false);
+  });
+});