Claude writes several types AFTER finishing a turn — `file-history-snapshot`, `attachment`, `pr-link`, `queue-operation`, `permission-mode`, `last-prompt`, `ai-title`, `agent-color`, `agent-name`, `custom-title`. Until now they fell through to the `default` switch branch and looked `active` for 30s, making finished sessions appear busy. This was almost certainly the root cause of "Claude looks like it's still working when it's done" reports (the #1908 family).
Add explicit cases mapping each to `ready`/`idle` by age, same as `assistant`/`summary`. Three existing tests that asserted these returned `active` were testing the buggy behavior — updated to the correct behavior, plus four new tests covering `attachment`, `permission-mode`, and `ai-title`.