Migrate Cypress E2E from cy.intercept to MSW service worker

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

cypress/e2e/fileOperations.cy.js

@@ -9,7 +9,7 @@ describe("File Operations", () => {
   beforeEach(() => {
     loginWithFixtures();
     cy.visit("/files");
-    cy.wait("@getFiles");
+    cy.contains("sample-process.xes").should("exist");
   });
 
   it("file list table has sortable columns", () => {