research: --fixed-rr-tp backtest flag + 2026-08-05 verdict (NOT shipped)

Hard TP at N×risk beats the trail on all 2024+ windows but the grid is
monotone to 3R (trend artifact) and M15 rr20 goes negative in 2021+2023
with doubled DD — trailing exits stay. Flag is research-only; its
Module 22 tests land with the next commit (shared test_all.py).

Claude-Session: https://claude.ai/code/session_017mbXs9HRawZhD1uZ3ze7zQ

CLAUDE.md

@@ -24,6 +24,8 @@ python backtest/gpu_backtest.py --pair XAUUSD --start 2025-01-01 --end 2025-06-0
     --primary-tf 15min --confirm-tfs 1h,4h
 # key flags: --spread --quality A+,A,B,C --strategies --workers --max-hold-bars
 #            --warmup-bars --cooldown-bars --no-cache --export-csv out.csv --detail
+#            --fixed-rr-tp N (research-only: hard TP at N×risk, trail off; verdict
+#            2026-08-05: NOT shipped — backtest/research/fixedtp_2026-08-05.md)
 ```
 
 **`test_all.py` is NOT pytest** — it uses a custom `@test("name")` decorator that runs each test immediately at import; don't grep for `def test_` or try `pytest test_all.py`. Run the whole file; it prints per-module results and exits non-zero on failure. There is no way to run a single test short of commenting modules out. Tests must stay green; every new gate/knob needs tests. When patching weekend logic in tests, patch `providers.base._is_forex_weekend` — but know there are THREE independent weekend implementations (`providers/base.py`, `signal_aggregator.py`, and an inline copy in `backtest/gpu_backtest.py:_is_xau_blocked_by_calendar`); patching the provider one does not reach the other two.