[bisubus]

Summary

• Correct cancelability erasure detection for unannotated async returns and callbacks with plain promise returns.
• Enforce structural detection boundaries for cancelable types.
• Broaden exhaustive catch validation to support discriminant switches and fallthrough bodies.
• Tighten listener leak tracking, shield option destructuring, and loop awaited steps.
• Run strict preset verification across the valid corpus.

Testing

• vitest: 2722 passed, 10 skipped across 91 test files.
• integration: 8/8 passed across test lanes 9 and 10.
• package smoke: passed across all import and require entry points.
• typecheck, lint, text style, range sweep, and banned token checks clean.