v0.1.0 — waterfall on a live pool

Senior and junior tranches on a simulated lending pool on devnet: deposits and
redemptions priced at NAV, yield split by the waterfall on a 43 200x model
clock, losses recorded by the operator and absorbed junior-first with an
immutable on-chain history. Pool page, deposit/redeem panel and operator loss
sheet in the web app; scripted end-to-end scenario from a fresh wallet in
73.6 s. Protection market and the what-if cabinet follow in v0.2.0 and v0.3.0.