malkhut(assets)+uv: system-wide asset directory + UV universe init

MALKHUT asset directory (malkhut/assets/): normalized canonical symbols,
KNOWN_EXCHANGES aux table (BINANCE/BINGX/BINGX_VST), per-exchange listing
status (TRADING/OFFLINE/UNKNOWN), JSON-backed, built for full-Binance-500
scale. Seeded with BLUE's NG7 feed universe (50 symbols) + live VST
contracts probe: 35 TRADING / 15 OFFLINE on VST (BAND, CELR, COS, CVC,
DENT, FUN, HOT, ICX, TFUEL, TUSD, USDC, WAN, WIN, XTZ, ZIL).
uv_asset_universe.init_asset_universe() = runtime tradable set for the
execution exchange; --onboard runs MALKHUT AssetCompiler for full taxonomy.
12 new tests, mutation-RED verified (status-filter + tradability guard).

MALKHUT/malkhut/tests/test_asset_directory.py

@@ -0,0 +1,90 @@
+"""
+Tests for malkhut.assets.directory — the system-wide asset universe store.
+
+Mutation-sensitivity: breaking normalize_symbol's uppercasing, listed_on's
+status comparison, or symbols_for_exchange's filter goes RED here.
+"""
+from __future__ import annotations
+
+import pytest
+
+from malkhut.assets.directory import (
+    KNOWN_EXCHANGES,
+    AssetDirectory,
+    ExchangeListing,
+    ListingStatus,
+    normalize_symbol,
+)
+
+
+def test_normalize_symbol_variants():
+    assert normalize_symbol("BAND-USDT") == "BANDUSDT"
+    assert normalize_symbol("band_usdt") == "BANDUSDT"
+    assert normalize_symbol(" eth/usdt ") == "ETHUSDT"
+    assert normalize_symbol("BANDUSDT") == "BANDUSDT"
+
+
+def test_known_exchanges_table_has_the_three_venues():
+    assert {"BINANCE", "BINGX", "BINGX_VST"} <= set(KNOWN_EXCHANGES)
+
+
+def test_listing_status_validated():
+    with pytest.raises(ValueError):
+        ExchangeListing(venue_symbol="X-USDT", status="LISTED")  # not a valid status
+
+
+def test_set_listing_rejects_unknown_exchange(tmp_path):
+    d = AssetDirectory(tmp_path / "d.json")
+    with pytest.raises(ValueError):
+        d.set_listing("BTCUSDT", "KRAKEN", status=ListingStatus.TRADING)
+
+
+def test_upsert_splits_base_quote_for_usdt():
+    d = AssetDirectory.__new__(AssetDirectory)
+    d.records = {}
+    rec = d.upsert("BANDUSDT")
+    assert rec.base == "BAND" and rec.quote == "USDT"
+
+
+def test_import_and_query_roundtrip(tmp_path):
+    p = tmp_path / "dir.json"
+    d = AssetDirectory(p)
+    n = d.import_symbols(
+        ["ETHUSDT", "BANDUSDT", "CELRUSDT"], "BINANCE",
+        status=ListingStatus.TRADING, checked_at="2026-07-11T20:00:00Z",
+        source="dolphin_ng7_scan_feed",
+    )
+    assert n == 3
+    d.set_listing("BANDUSDT", "BINGX_VST", venue_symbol="BAND-USDT",
+                  status=ListingStatus.OFFLINE, source="vst_contracts_probe")
+    d.set_listing("ETHUSDT", "BINGX_VST", venue_symbol="ETH-USDT",
+                  status=ListingStatus.TRADING, source="vst_contracts_probe")
+    d.save()
+
+    d2 = AssetDirectory(p)  # reload from disk
+    assert len(d2) == 3
+    assert d2.symbols_for_exchange("BINANCE") == ["BANDUSDT", "CELRUSDT", "ETHUSDT"]
+    # BAND is OFFLINE on VST → excluded from the tradable set
+    assert d2.symbols_for_exchange("BINGX_VST") == ["ETHUSDT"]
+    assert d2.symbols_for_exchange("BINGX_VST", status=ListingStatus.OFFLINE) == ["BANDUSDT"]
+    assert d2.venue_symbol("ETHUSDT", "BINGX_VST") == "ETH-USDT"
+    assert d2.venue_symbol("BANDUSDT", "BINGX") == ""  # never probed on live BingX
+    assert d2.get("band-usdt").listed_on("BINANCE") is True
+    assert d2.get("band-usdt").listed_on("BINGX_VST") is False
+
+
+def test_import_is_idempotent(tmp_path):
+    d = AssetDirectory(tmp_path / "d.json")
+    d.import_symbols(["ETHUSDT"], "BINANCE")
+    d.import_symbols(["ETHUSDT"], "BINANCE")
+    assert len(d) == 1
+    assert d.symbols_for_exchange("BINANCE") == ["ETHUSDT"]
+
+
+def test_listing_on_second_exchange_preserves_first(tmp_path):
+    d = AssetDirectory(tmp_path / "d.json")
+    d.import_symbols(["ETHUSDT"], "BINANCE")
+    d.set_listing("ETHUSDT", "BINGX_VST", venue_symbol="ETH-USDT",
+                  status=ListingStatus.TRADING)
+    rec = d.get("ETHUSDT")
+    assert set(rec.exchanges) == {"BINANCE", "BINGX_VST"}