- Fix color blending truncation in blend(): compute the full weighted
sum as float64 before casting to uint8, avoiding double truncation
- Fix UC8159 on IMPRESSION57 incorrectly reporting height as 447;
correct it to 448 in DetectOpts
- Add Opts.String() for human-readable option printing
- Refactor update() if/else chain to a switch statement
- Add TestDevImpression_BlendPrecision to cover the blend fix
Signed-off-by: Çağlar Onur <caglar@10ur.org>