docs: sync ledger cross-ref + glossary to the C10 rework (refs #116)

Follows the C10 rework (29cdc8c). C15: the deploy-grade geometry fields now defer
to the cost model's currency→R normalization / the live deploy edge, not the
retired Stage-2 realistic broker. Glossary: "realistic broker" and "Stage 1 /
Stage 2" marked superseded (kept as history); bias/broker/equity-stream/position-
table/R/R-metrics/R-evaluator/RiskExecutor/Sizer/sim-optimal-broker/veto reworked
to the cost-model-in-R model; added cost model, gross R, net R, net-R equity
curve, conviction-based risk allocation.

docs/design/INDEX.md

@@ -957,8 +957,8 @@ removed that floor**: with the sidecar geometry supplying the real-path pip, the
 authored table was redundant, so `InstrumentSpec` / `instrument_spec` / the vetted
 list were deleted. The speculative deploy-grade fields and the override/floor tiers
 of the #124 hierarchy (tier 1 authored override, tier 3 authored floor) are
-**deferred** until a consumer — the Stage-2 realistic broker — needs them, read from
-the sidecar geometry then. The `quote_currency` runtime-type transition is likewise
+**deferred** until a consumer — the cost model's currency→R normalization (C10), or
+the live deploy edge (real broker) — needs them, read from the sidecar geometry then. The `quote_currency` runtime-type transition is likewise
 deferred to that consumer; #124 collapses to **recorded sidecar geometry → refuse**
 in the meantime.