fix(packaging): bundle built-in lexicons in wheel

[fight18-ui]

Summary

The PyPI codd-dev 3.37.0 wheel contains 0 codd_plugins files, while the matching source/sdist contains 39 lexicon manifests. This leaves a clean installation with codd lexicon list reporting Installed 0 / Available 0, and a coverage check using api_rest_openapi fails with Unknown lexicon (exit 2).

The cause is that the wheel target selects only packages=["codd"], so the top-level codd_plugins data tree is omitted. This PR adds one Hatch force-include mapping for codd_plugins and an artifact-level regression test.

Verification

• The regression test builds the real wheel and compares the complete source and archive manifest-path sets (39 manifests), not just a count.
• It also asserts all 6 api_rest_openapi files and codd_plugins/stack_map.yaml are in the archive.
• A clean venv, installed from the built wheel with --force-reinstall --no-deps, reports Available 39 and includes api_rest_openapi when run outside the clone with PYTHONPATH empty and Python isolated mode.
• line_harness codd coverage check completes with exit 0 and no Unknown lexicon.
• Task unit/build/coverage checks have 0 skips.

Scope

This changes no runtime API, LexiconManager behavior, lexicon schema, coverage threshold, or version. The fork artifact is pinned only for internal recovery; this PR does not publish to PyPI. Merge, release, versioning, and publication timing remain entirely at the upstream maintainer’s discretion.