jextract/jni: Protocol property setters reference an incorrectly named adapter #949

Problem

With Java callbacks enabled, JNI bindings for a public protocol-typed property can generate a Swift setter that references a wrapper class under a different name from its declaration. The generated Swift code then fails to compile.

Example

public protocol Callback {
  func value() -> Int64
}

public final class Service {
  public var callback: any Callback

  public init(callback: some Callback) {
    self.callback = callback
  }

  public func read() -> Int64 {
    callback.value()
  }
}

The generated wrapper declaration uses the Swift property name, while the setter's argument conversion uses the Java setter name:

// Generated wrapper declaration
final class _Service_callback_newValue_Wrapper: SwiftJavaCallbackWrapper {
  // ...
}

// Generated setter argument conversion references
// _Service_setCallback_newValue_Wrapper instead.

The same kind of mismatch can occur when Java method names differ from Swift names for label-disambiguated overloads or Java keywords.

Related: #946 also concerns protocol-parameter adapters, but reports duplicate declarations for overloads.

Reference workaround implementation: qoncept#16