chore(release): 0.0.7

Squash-merge lib-standardisation: adopt repo standards across packaging,
tooling, docs, and CI.

- standardize pyproject.toml (canonical packaging, lint config, extras, GSDFC pydoclint)
- add py.typed marker, modernize type hints and Google-style docstrings
- nest generated docs under docs/lib and docs/mcp; add hand-written wiki
- adopt standard Type A PyPI CI pipeline (tag==version guard + quality gate)
- promote generated CHANGELOG.md; bump version to 0.0.7

openapi_first/templates/model_app/data.py

@@ -62,6 +62,8 @@ def get_item(item_id: int) -> Item:
     KeyError
         If the item does not exist.
     """
+    if item_id not in _items:
+        raise KeyError(item_id)
     return _items[item_id]
 
 
@@ -134,4 +136,6 @@ def delete_item(item_id: int) -> None:
     KeyError
         If the item does not exist.
     """
+    if item_id not in _items:
+        raise KeyError(item_id)
     del _items[item_id]