Per sub-project-2 plan Task 7 / spec §7. HeuristicProposer seeds the brain plane
from archive priors and the mood plane from title/description keyword nudges,
clamps to 0..4, and emits a one-line rationale. Deterministic, no I/O, no ML
(honors design §11) — only a DRAFT a human reviews.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Ben Stull