The economy organ was the least-documented named component in the
architecture — one line in bus-topology.md, a Pony primitive, and a
smoke-test wire. This adds 8 plan specs following the 10-section template:
M0 hub, M1 ingestion, M2 digestion core (small-model),
M3 cost ledger, M4 budget governor, M5 context yield,
M6 provenance chain (S1/S2 compliance), M7 outer-bus exchange.
Also updates the plans README index and integration DAG, and resolves
bus-topology.md's open item about the organ's placement.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
