ellmercodex v0.1.2

Release v0.1.2 adds asynchronous Chat methods, async tool modes and callbacks, cancellation-controller support, and image/PDF content preservation while retaining the Codex compatibility layer's experimental status. Known gaps are documented in the README: exact echo="all" semantics, full streamed/tool metadata, rich output inside the custom tool loop, batch/parallel helpers, and provider-native tools.