docs(utas-host): record economy cutover progress in route-authority gate

Core economy HTTP API + host CoreEconomy client (fail-closed) + credits reader
landed; classifier not yet flipped (coherent barrier pending full cluster + Core
seed).

openfut-utas-host/ROUTE_AUTHORITY.md

@@ -77,3 +77,22 @@ After cutover, every remaining `Python (proxied)` route MUST have
 `economy state touched = NONE`. Routes with `economy state touched != NONE` are
 part of the migration cluster and MUST be Rust before R1. This table is the
 audit source; the host `classify()` is the enforcement point (NEVER BOTH).
+
+## Cutover progress (2026-08-13)
+
+Landed (Core authority + transport + first reader; classifier NOT yet flipped):
+
+- **Core economy HTTP API** (`d32dc6e`): generic `/economy/{balance,entitlements,
+  purchase-entitlement,redeem-entitlement,sell-item,grant-reward,purchase-item}`,
+  server-side club resolution, atomic transactions. Core matrix green.
+- **Host `CoreEconomy` client** (`d240a61`): typed reqwest transport, **fail-closed,
+  no Python fallback** by contract.
+- **`/user/credits` handler** (`handle_credits`): Core-backed, oracle-shape body,
+  503 fail-closed. Tested via `FakeEconomy`.
+
+**Not flipped:** `classify()` still routes every economy route to Python. Per the
+single-writer rule the flip is one coherent barrier once ALL writers+readers are
+implemented and Core is seeded — a partial flip would desync coins. Remaining
+handlers: purchasegroup full-gen, userMassInfo economy, Store BUY, pack-open,
+quick-sell, market buy/list/cancel, match reward; then the barrier flip +
+differential/concurrency/restart + no-fallback classifier tests.