personal memory agent

release: solstone 0.6.7 master

Folds in the post-0.6.6-tag work (12 commits): imported-audio activity auto-roll + activities_review retirement, weekly_reflection real-streams fix + synthesis access-tier, settings config-write-lock serialization, schedule-command heal migration 007, segment change-detection + redundant-segment short-circuit, CLI both-arg-forms, journal search loud-fail on unknown agent. CHANGELOG via the CMO changelog-voice recipe; sensitive-content: no. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>