fix(e2e): use :text-is selector for Workspace label in create-project dialog

getByLabel('Workspace') fails because FakeMUI Select renders a custom
div-based dropdown without a real <input id>, so Playwright cannot resolve
the label→control association. Use :text-is('Workspace') to match the
FormLabel element directly with exact text, avoiding substring match on
the breadcrumb 'Workspaces' link.

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

frontends/workflowui/playwright/templates.json

@@ -183,7 +183,7 @@
         {
           "description": "Verify workspace dropdown visible",
           "action": "expect",
-          "label": "Workspace",
+          "selector": ":text-is('Workspace')",
           "assertion": {
             "matcher": "toBeVisible"
           }