stabilize async coroutines and node stream compatibility

• fix async generator await/yield, overlap, and reentrant next semantics
• harden coroutine teardown, active async tracking, and queued microtask rooting
• fix JIT lexical-this handling for closure-heavy callback paths
• improve Node compatibility for fs/promises FileHandle, util.promisify, and EventEmitter listeners()
• fix stream lifecycle regressions around flowing startup, Transform callbacks, and tty ReadStream state ownership