[Gambit-Checkmate]

Fixes #449.

Forward keyword arguments from over_args to the wrapped function. Transforms apply to the corresponding positional arguments. The wrapper's receiver is positional-only so a keyword named self can reach the target.

Use Concatenate to describe the transformed positional prefix and preserve the remaining parameters in the callable type. The chain annotations are regenerated from those overloads.

• Two runtime regressions fail on 1cf4661 and pass with the patch. They cover a required keyword-only parameter and a keyword named self.
• Six focused mypy/runtime test items pass, covering direct and chained calls, the remaining positional and keyword-only parameters, and the existing transform arities.
• Windows CPython 3.13.13 full runtime unit and doctest suite: 3,314 passed, 100% coverage. The configured mypy, Ruff, Sphinx, package builds and diff checks passed. A Linux Python 3.10.12 smoke test passed.

OpenAI Codex assisted with the investigation, implementation and tests.

[coveralls]

coverage: 100.0%. remained the same — Gambit-Checkmate:fix/over-args-keyword-forwarding into dgilland:develop