chore: keep only what the system needs — drop research tooling, study scripts, diagram, plan

Owner directive 2026-09-06: Dukascopy and similar research material is irrelevant to
the running system; keep only code and files with a role in system functioning.

Deleted (all in git history before this commit):
- backtest/research/ tooling and data: book_report, book_diff, burst_map,
  burst_precursors, burst_indicator_map, open_trade_bursts, calendar_impact,
  watch_rule_eval, sizing_model, commit_ladder, llm_news_eval + llm_news_golden.csv,
  ff_calendar_scraper, duka_spread + duka_spread_by_hour.csv (the Dukascopy spread
  study), feed_divergence_oanda_vs_tiingo.csv, the panel dry-test JSONL, __init__.py
- scripts/feed_divergence_study.py, scripts/signal_parity_study.py (completed studies;
  their reports keep the results)
- docs/architecture.png + architecture_diagram.py (developer illustration)
- docs/data_source_change_test_plan.md (Phase 4 shadow scan stays noted in CLAUDE.md)

Kept: the campaign .md reports in backtest/research/ as the decision ledger CLAUDE.md
cites (rule 1 evidence); scripts/shadow_scan.py (pending operational step);
backtest/diagnose_filters.py (test-locked backtester diagnostic).

Local, untracked material removed on this box: .superpowers/, walkforward/, baseline/,
the commit-ladder and LLM-eval result folders, the Dukascopy boundary CSV; the
sizing_2026-09 folder is pruned to the four 3-year baseline books CLAUDE.md names.

.gitignore no longer lists the removed research outputs; the backtest instructions
and CLAUDE.md no longer point at deleted tools.

Suite: 461 passed, 0 failed (nothing imported the removed files).

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0156YhogLytzj9P2iH1skGbL

backtest/research/signal_parity_2026-08-14.md

@@ -1,7 +1,7 @@
 # Signal-Level Replay Parity — Oanda vs Tiingo (Phase 2)
 
 **Date:** 2026-08-14
-**Tool:** `scripts/signal_parity_study.py` (replays real `analyze_from_dataframes`, news off)
+**Tool:** `scripts/signal_parity_study.py` (script removed 2026-09-06, in git history) (replays real `analyze_from_dataframes`, news off)
 **Window:** 2025-08-14 → 2026-08-14 (12 months); M15 stride 8, M5 stride 24 → ~2,900 sampled decisions each
 **Preceding:** Phase 1 price-diff study (`feed_divergence_2026-08-14.md`)