feat: 15% monthly return target — infrastructure + daily signal resampling

Phase 1 — Infrastructure:
- RiskMgmt_RISK_PER_TRADE 0.5% → 1.5% (vbt_backtest.py)
- min_monthly_return_pct=15% acceptance filter (strategy_orchestrator)
- --min-monthly-return 15 CLI option (nexquant.py)
- {{ min_monthly_return }}% in strategy prompts
- MIN_MONTHLY_RETURN_PCT=15.0 in gen_strategies_real_bt + smart_strategy_gen
- realistic_backtest_all.py target_monthly 4→15%

Phase 2 — Factor quality:
- IC thresholds: prompt 0.05→0.08, bandit IC weight 0.10→0.20
- Explicite IC > 0.04 target in RAG prompt
- min_ic filters: data_loader 0.0→0.04, strategy_worker 0.02→0.04, ml_trainer 0.01→0.04

Architecture fix — Daily signal resampling:
- Factors have IC at daily resolution, but z-scores on 1-min collapse IC to ~0
- Resample factors to daily before strategy exec, ffill signal to 1-min for backtest
- Walk-forward IS years 3→1 (only 2 years of data available)
- Removed broken intersection() logic that destroyed 99.99% of 1-min data
- ffill stale propagation limited to 2880 bars (2 trading days)
- Fixed logger crash in _load_strategies
- Preflight: removed constant-signal check (false positive on random sandbox data)
- Tests: test_daily_signal_resampling.py (8 tests)

Non-negotiable rules: R1-R10 in AGENTS.md

rdagent/components/backtesting/vbt_backtest.py

@@ -42,8 +42,8 @@ EXTREME_BAR_THRESHOLD = 0.05  # |ret| > 5% on a single 1-min bar → suspicious
 FTMO_INITIAL_CAPITAL   = 100_000.0
 FTMO_MAX_DAILY_LOSS    = 0.05   # 5%  of initial → block new trades rest of day
 FTMO_MAX_TOTAL_LOSS    = 0.10   # 10% of initial → simulation ends
-# Risk-based position sizing: 0.5% equity risk per trade, 10-pip stop, max 1:30 leverage
-FTMO_RISK_PER_TRADE    = 0.005
+# Risk-based position sizing: 1.5% equity risk per trade, 10-pip stop, max 1:30 leverage
+FTMO_RISK_PER_TRADE    = 0.015
 FTMO_STOP_PIPS         = 10
 FTMO_PIP               = 0.0001
 FTMO_MAX_LEVERAGE      = 30
@@ -343,7 +343,7 @@ def _apply_ftmo_mask(
 OOS_START_DEFAULT = "2024-01-01"
 
 # Rolling walk-forward default windows (IS years, OOS years, step years)
-WF_IS_YEARS  = 3
+WF_IS_YEARS  = 1
 WF_OOS_YEARS = 1
 WF_STEP_YEARS = 1