Adds knowledge_pages (db migration 118→119) + a deterministic, model-free
keyword index of task/PR history in packages/dashboard/src, incrementally
refreshed on task completion (task:moved→done listener) and queryable via an
auth-gated, project-scoped API. Complements the LLM-extracted insights/memory
surfaces rather than duplicating them.
Follow-ups: no React view yet; PR-history page population attaches via U18.
0a87890bd8