Resume transformed awaits at the continuation boundary

[MiguelsPizza]

Why

The compile-time await transform introduced in #22 restored actor identity before resolving each await and cleared it one microtask later. A nested native promise continuation could run after that window but before the input lock checkpoint ended, so a later transformed await no longer knew which actor owned the continuation.

This surfaced under load in the Rook cutover (Rook #143) as SQL writes running without the input lock during root-agent tool/action flows.

What changed

• transformed awaits now return a captured outcome
• the generated continuation restores actor identity at its first post-await instruction
• identity remains available until the same checkpoint boundary that releases the input lock
• the legacy gate and async-iterable path remain compatible

Verification

• 799 unit tests
• TypeScript builds and conformance examples
• publint, attw, and package smoke test
• Fallow: no introduced dead code, complexity, or duplication
• Rook root-agent Chromium integration: 15/15 passes under 12 concurrent CPU burners; the old implementation failed within 1-3 attempts