v0.3.0 - onboarding v2

Progressive foundation: the first sitting is 15-20 minutes and ends with real drafts; the rest of the foundation spreads across week one, with resume state. New /adopt skill turns an existing body of notes (Obsidian, Notion, journals) into bounded first-corpus candidates, read-only over your source. Cadence coherence reports now persist to your-life/reviews/coherence/ with streak and delta trends, and the overdue nudge points at the latest one. Try it before telling the system anything: python scripts/coherence.py examples/sam-rivers. See CHANGELOG.md and UPGRADING.md to pull these into an existing fork.