Rename path parameter {token} to {eventToken} in OpenAPI spec

Aligns the path parameter naming with the value object convention
used throughout the codebase (eventToken, rsvpToken, organizerToken).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/views/__tests__/EventDetailView.spec.ts

@@ -280,8 +280,8 @@ describe('EventDetailView', () => {
     await flushPromises()
 
     // Verify API call
-    expect(vi.mocked(api.POST)).toHaveBeenCalledWith('/events/{token}/rsvps', {
-      params: { path: { token: 'test-token' } },
+    expect(vi.mocked(api.POST)).toHaveBeenCalledWith('/events/{eventToken}/rsvps', {
+      params: { path: { eventToken: 'test-token' } },
       body: { name: 'Max' },
     })