[fly1d]

For C extends B implements A, member resolution can select A's method even when B supplies an implementation with a narrower return type. For example, an interface returning Foo hides an inherited method returning the subtype Bar.

Prefer a public class declaration over an earlier interface declaration with the same method key. Resolve its return and argument types in the class's generic context, while retaining the existing hierarchy order and inheritable annotation priority. Direct annotations and mix-in overrides are applied to the selected declaration.

Fixes #57.

Added 18 tests covering covariant and generic returns, direct overrides, default and abstract methods, filtering, and method/parameter annotations. The same tests give 13 failures and 5 passing controls on the original code, then all pass with the fix.

./mvnw clean verify passes on OpenJDK 17.0.20 with the wrapper's Maven 3.9.11: 375 tests, no failures, errors or skips. This includes packaging, module metadata, coverage and Javadoc generation; the POM and Java 8 source/target settings are unchanged.