opaque-ke

Summary This PR introduces an internal marker trait and uses it to centralize the block-size constraints required by and . It also clarifies documentation by explicitly distinguishing a hash function's internal block size from its digest output size. Changes Add Add a blanket implementation for types satisfying the block-size requirements Replace duplicated typenum bounds in and Improve documentation around block-size constraints and Motivation The same typenum constraints were repeated across multiple trait definitions and implementations: Centralizing these constraints: Reduces duplication Improves readability of trait signatures Provides a single source of truth for block-size requirements Simplifies future maintenance The documentation updates also make it explicit that the constraint applies to a hash function's internal block size () rather than its digest output size. Compatibility This change is purely a refactor and documentation improvement. There are no functional, behavioral, or public API changes.

Adding a minor spacing update to the README to test the PR workflow.