Contracts now live directly on definitions via @ / =@ annotations and
travel automatically with exported values.
- Remove !export from lexer/parser/AST/evaluator/manifest/resolver and CLI.
- Simplify workspace module export logic: export all top-level local
definitions by default.
- Update Frontend.ContractDesugar:
- Named binder annotations (x@nat?) expand to per-argument withContract.
- Phantom annotations (@nat?) expand to a local raw helper plus a wrapper,
keeping fixed points shared and only depending on withContract.
- Merge lib/guardedBase.tri into lib/base.tri and annotate partial/sensitive
base functions: head, tail, last, add, sub, mul, div, mod, pow, min,
max, length, sum, product.
- Add check contract helper to lib/base.tri.
- Update demos/contractBasics.tri and README to reflect @/=@-only design.
- Update test suite: remove guardedBase import, replace explicit !export
test with a test verifying that contract annotations on an exported
definition are enforced on import.
- Fix remaining base.tri definitions (div/mod/pow) to stay point-free.
