Cheap insurance for the day someone widens the WHERE clause in findRolledUpActivityFeed. Suggested by Sara in PR #288 review cycle 1. Inserts two non-eligible events alongside one TEXT_SAVED and asserts the feed returns the TEXT_SAVED row only. Part of #285. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>