feat: robust-momentum strategies live; fix live universe, lots and UI backtests

Strategies
- BarStrategy protocol (close/open/high/low/volume bars; row d uses bars
  through d-1) and RobustMomentumStrategy: overnight_recovery_top10 (US),
  lowrisk_momentum_top15 and lowbeta_sharpe_mom_top20 (CN), top-N with
  rank hysteresis, 10-day rebalance, weights drift between rebalances.
- trader: strategy_fields/strategy_bars/bar_session_weights; one signal
  path (_signals_for_sessions) replaces generate_target_weights.

Live fixes
- CSI 300 constituents come from China Securities Index's file; the
  Wikipedia table was 122 names off the real index.
- S&P 500 change log moved to "Historical components of the S&P 500".
- data_manager: tickers missing from a partial Yahoo batch are retried
  alone before being marked unavailable (CEG, GEV, SNDK ... were dropped).
  update() takes fields=[...] and stores high/low/volume panels.
- Whole-lot orders go to the nearest lot within cash (CN books held ~62%
  cash); held names are resized only beyond RESIZE_BAND (10%), so books no
  longer pay a ticket fee to trade daily drift.

Web backtests
- backtest_runner.py replaces the duplicated bridge/precompute code: PIT
  membership in both markets (data/csi300_history.json), stock universe
  limited to index members (ETFs and benchmarks in the shared panel were
  pickable), and the book kept like the live trader (simulate_live_book:
  signal timing, drift, order floor, resize band, fees on orders placed).

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

uv.lock

@@ -770,6 +770,7 @@ dependencies = [
     { name = "numpy" },
     { name = "pandas" },
     { name = "scipy" },
+    { name = "xlrd" },
     { name = "yfinance" },
 ]
 
@@ -780,6 +781,7 @@ requires-dist = [
     { name = "numpy", specifier = ">=2.4.0" },
     { name = "pandas", specifier = ">=2.3.3" },
     { name = "scipy", specifier = ">=1.17.1" },
+    { name = "xlrd", specifier = ">=2.0.2" },
     { name = "yfinance", specifier = ">=1.0" },
 ]
 
@@ -935,6 +937,15 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/fa/a8/5b41e0da817d64113292ab1f8247140aac61cbf6cfd085d6a0fa77f4984f/websockets-15.0.1-py3-none-any.whl", hash = "sha256:f7a866fbc1e97b5c617ee4116daaa09b722101d4a3c170c787450ba409f9736f", size = 169743, upload-time = "2025-03-05T20:03:39.41Z" },
 ]
 
+[[package]]
+name = "xlrd"
+version = "2.0.2"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/07/5a/377161c2d3538d1990d7af382c79f3b2372e880b65de21b01b1a2b78691e/xlrd-2.0.2.tar.gz", hash = "sha256:08b5e25de58f21ce71dc7db3b3b8106c1fa776f3024c54e45b45b374e89234c9", size = 100167, upload-time = "2025-06-14T08:46:39.039Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/1a/62/c8d562e7766786ba6587d09c5a8ba9f718ed3fa8af7f4553e8f91c36f302/xlrd-2.0.2-py2.py3-none-any.whl", hash = "sha256:ea762c3d29f4cca48d82df517b6d89fbce4db3107f9d78713e48cd321d5c9aa9", size = 96555, upload-time = "2025-06-14T08:46:37.766Z" },
+]
+
 [[package]]
 name = "yfinance"
 version = "1.0"