Add processor recording-context tests

Expand custom processor test coverage around recording context and save-path behavior. This adds a new test module for BaseProcessorSocket and DLCLiveMainWindow recording hook interactions, including optional hook handling and processor lookup paths.

The existing base processor tests were also cleaned up to use pytest `tmp_path` for file outputs instead of writing into module data directories, remove manual cleanup blocks, and tighten assertions/formatting for save and recording flows.

Author: C-Achard