Rename desktop e2e scripts and tags for consistency (#7240)

* Rename desktop e2e scripts and tags for consistency

* Show local command in main test step

* Restore 'e2e' prefix to clarify GitHub UI

* Add web script to contributor guide

e2e/playwright/prompt-to-edit-snapshot-tests.spec.ts

@@ -63,7 +63,7 @@ test.describe('edit with AI example snapshots', () => {
   test(
     `change colour`,
     // TODO this is more of a snapshot, but atm it needs to be manually run locally to update the files
-    { tag: ['@electron'] },
+    { tag: ['@desktop'] },
     async ({ context, homePage, cmdBar, editor, page, scene }) => {
       const project = 'test-dir'
       await context.folderSetupFn(async (dir) => {