fix(vitepress): do not re-set routing on re-enhance

vue setRoutingStrategy targets last-installed app; calling it
again from app1 after app2 install clobbers app2's adapter.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: s00d

packages/vitepress/src/create.ts

@@ -126,9 +126,8 @@ export function createVitePressI18n(options: VitePressI18nOptions): CreateVitePr
       state = { adapter, boundSyncHandler: null, chainedPrevious: undefined }
       byApp.set(app, state)
     }
-    else {
-      plugin.setRoutingStrategy(state.adapter)
-    }
+    // Re-enhance: do not call setRoutingStrategy — vue's setter targets last-installed
+    // currentApp and would overwrite another app's router injection.
     lastAdapter = state.adapter
 
     if (!syncWithVitePress) return

packages/vitepress/tests/with-i18n-micro.test.ts

@@ -310,4 +310,37 @@ describe('createVitePressI18n', () => {
     expect(app1.use).toHaveBeenCalledTimes(1)
     expect(app2.use).toHaveBeenCalledTimes(1)
   })
+
+  it('does not re-set routing strategy on re-enhance (avoids clobbering other apps)', () => {
+    const { enhanceApp, plugin } = createVitePressI18n({
+      locale: 'en',
+      defaultLocale: 'en',
+      locales: [{ code: 'en' }, { code: 'fr' }],
+      messages: { en: { hi: 'Hi' }, fr: { hi: 'Salut' } },
+      syncWithVitePress: false,
+    })
+    const setSpy = vi.spyOn(plugin, 'setRoutingStrategy')
+
+    const makeApp = () => ({
+      use: vi.fn(),
+      provide: vi.fn(),
+      config: { globalProperties: {} as Record<string, unknown> },
+      component: vi.fn(),
+    })
+    const makeRouter = (path: string) => ({
+      route: { path },
+      go: vi.fn(),
+      onAfterRouteChange: undefined as ((to: string) => unknown) | undefined,
+    })
+
+    const app1 = makeApp()
+    const app2 = makeApp()
+    enhanceApp({ app: app1 as never, router: makeRouter('/') as never })
+    enhanceApp({ app: app2 as never, router: makeRouter('/fr/') as never })
+    const afterTwo = setSpy.mock.calls.length
+    expect(afterTwo).toBe(2)
+
+    enhanceApp({ app: app1 as never, router: makeRouter('/') as never })
+    expect(setSpy.mock.calls.length).toBe(afterTwo)
+  })
 })