Worker Code 0.1.0: bounded execution on Workers

Bounded QuickJS WASM execution through ordinary Pi Durable tools, with exec/wait, immutable module snapshots, pure evaluation and impure tool-owned handlers. Includes pinned WASM and upstream license notices. Real workerd workflows cover isolation, limits, concurrency, hooks, results, cancellation and isolate-wide admission. This is a separate Worker execution mode, not native Code or Notebook parity.