[dbrattli]

Summary

Make the exported typing contracts usable from caller code and include the PEP 561 marker in the wheel. Monad and Applicative now name their concrete result containers, so structural assignments can be checked without widening the concrete APIs to Any. Add caller-side Pyright checks for the supported families.

Correct the wrapped-function apply signatures and add overloads for unary and two-argument functions. Two-argument application still curries; a TypeError raised inside a unary function now propagates instead of being mistaken for a currying request.

Writer.map now transforms its value while preserving the log. Writer.map_with_log retains the old tuple-transforming operation. Writer.unit exposes its string-log default in its return type and accepts empty_log for other log types.

Typing and API changes

• Monad[T] becomes Monad[T, Result], where Result is the concrete container returned by bind.
• Applicative[T] becomes Applicative[WrappedFunction, ArgumentContainer, ResultContainer].
• Functor[T] describes same-type map operations; concrete classes still type their value-changing map methods.
• Callers whose Writer.map callback transforms (value, log) should use Writer.map_with_log.
• Writer.unit(value) is typed as returning a string-log writer. Pass empty_log for another log type, or use a writer class created with Writer.create.