[rogeralsing]

Fixes #8.

xUnit worker runs can appear to filter out all tests when non-protocol output is written to stdout, causing JSON-line parsing to stop early.

Changes:

• Reserve worker stdout for protocol by redirecting Console.Out to stderr in the worker.
• Make the coordinator ignore non-protocol stdout lines instead of treating them as EOF.
• Add regression coverage with a sample xUnit assembly that emits stdout noise during load.