Run one of four scripted scenarios. No real engines are called; time and costs are mocked and illustrative.
Pick a scenario and press Run task. Expected user action: Accept.
User gives a task (pending)
Price and cap shown (pending)
Reserve units (pending)
Fast engine drafts the change (pending)
Verification: build, tests, browser run (pending)
Cross-check by a second engine (pending)
Diff, evidence and price shown (pending)