Implement RotatingFileSink in hierarchy

You are given an existing Python 3.10 codebase with an abstract base class RecordSink (from abc import ABC, abstractmethod) that defines open() -> None, write(record: dict) -> None, and close() -> None. A Pipeline class instantiates a sink, calls sink.open() once, then for each record calls sink.write(record), and finally calls sink.close(); Pipeline must not be modified. Implement a new concrete RotatingFileSink that: (1) writes each record as a compact JSON line (UTF- 8) to disk, (2) rotates to a new file when either a maximum number of lines N is reached or total bytes exceed limit L, using filenames like prefix_00001.log, prefix_00002.log, etc., (3) supports use as a context manager via enter/exit while preserving existing open/close semantics, (4) is safe for concurrent write() calls from multiple threads using a lock, (5) raises a custom SinkClosedError if write() is invoked after close(), and (6) adheres to Liskov substitution so Pipeline works unchanged. Do not alter existing method signatures or the Pipeline. Provide the full class implementation and a brief unit test showing rotation and thread-safety.