a5a35648d7
Treat a generator task as completed when it produces artifacts, when a task message reaches a terminal state, or when the project is ready — even if the project is still exploring another concurrent thread. Adds generatorTaskMessageCompleted to classify terminal task messages and covers ready-without-messages and concurrent-thread cases with tests. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>