Skimmable

Review the change as if a tired reviewer must understand it in one fast pass.

Prefer deleting code to explaining code.

Keep the pass narrow: improve readability, state modelling, and diff clarity without changing product behaviour unless the current behaviour is obviously dead, redundant, or inconsistent with types.

Checklist

Apply these rules aggressively:

1. Make the code obvious on first read.
2. Reduce the number of states the code can represent.
3. Reduce parameter count.
4. Remove optional parameters unless they are truly required by callers.
5. Replace boolean flags and loose option bags with discriminated unions when behaviour differs by mode.
6. Handle every known variant exhaustively.
7. Fail on unknown variants immediately.