feat: Pattern Lab — historical backtest engine for pattern discovery

- Remove all built-in patterns (no proof of legitimacy); seed_builtin_patterns is now a no-op
- DB: add backtest_lab_runs table + backtest_hits/runs_count columns on patterns
- services/pattern_lab.py: build_historical_context (yfinance + RSI/MA200),
  run_ai_backtest (GPT-4o as historical analyst), evaluate_outcomes (actual moves at T+horizon)
- routers/pattern_lab.py: POST /run, POST /evaluate/{id}, GET /runs, DELETE /runs/{id},
  POST /save-pattern (promotes hit pattern to library with reliability counters)
- PatternLab.tsx: 34 preset events 2015-2025 (macro/geo/credit/fx/commodities/volatility/tech),
  3-panel layout — preset selector + wizard + run history, market data table,
  AI pattern cards with hit/miss outcome display, Save to Library button
- useApi.ts: usePatternLabRuns, useRunPatternLab, useEvaluatePatternLab, useSaveLabPattern, useDeleteLabRun
- Sidebar + App.tsx: /pattern-lab route + FlaskConical nav link

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/services/database.py

@@ -83,12 +83,39 @@ def init_db():
         "ALTER TABLE custom_patterns ADD COLUMN signal_direction TEXT",
         # Pattern Explorer — taxonomy tree path
         "ALTER TABLE custom_patterns ADD COLUMN taxonomy_path TEXT DEFAULT '[]'",
+        # Pattern Lab — backtest reliability tracking
+        "ALTER TABLE custom_patterns ADD COLUMN backtest_hits INTEGER DEFAULT 0",
+        "ALTER TABLE custom_patterns ADD COLUMN backtest_runs_count INTEGER DEFAULT 0",
+        # Remove all built-in patterns (no proof of legitimacy)
+        "DELETE FROM custom_patterns WHERE source = 'builtin'",
     ]:
         try:
             c.execute(_sql)
         except Exception:
             pass
 
+    # Pattern Lab — historical backtest runs
+    c.execute("""CREATE TABLE IF NOT EXISTS backtest_lab_runs (
+        id TEXT PRIMARY KEY,
+        preset_id TEXT,
+        theme TEXT NOT NULL,
+        analysis_date TEXT NOT NULL,
+        horizon_days INTEGER NOT NULL,
+        assets TEXT NOT NULL,
+        theme_hint TEXT,
+        context_snapshot TEXT,
+        ai_result TEXT,
+        outcome TEXT,
+        status TEXT DEFAULT 'pending',
+        error_msg TEXT,
+        created_at TEXT DEFAULT (datetime('now')),
+        evaluated_at TEXT
+    )""")
+    try:
+        c.execute("CREATE INDEX IF NOT EXISTS idx_blr_date ON backtest_lab_runs(analysis_date DESC)")
+    except Exception:
+        pass
+
     # Phase 4.2 — Régime clusters (K-Means sur gauges macro)
     c.execute("""CREATE TABLE IF NOT EXISTS regime_clusters (
         id INTEGER PRIMARY KEY AUTOINCREMENT,
@@ -885,37 +912,8 @@ def update_position_notes(pos_id: str, notes: str):
 # ── Custom Patterns ────────────────────────────────────────────────────────────
 
 def seed_builtin_patterns(builtin_patterns: List[Dict[str, Any]]):
-    """Seed built-in patterns into DB (idempotent). Always updates taxonomy_path."""
-    conn = get_conn()
-    existing = {r[0] for r in conn.execute("SELECT id FROM custom_patterns").fetchall()}
-    for p in builtin_patterns:
-        taxonomy_json = json.dumps(p.get("taxonomy_path", []))
-        if p["id"] not in existing:
-            conn.execute("""INSERT INTO custom_patterns (
-                id, name, description, triggers, keywords, historical_instances,
-                suggested_trades, asset_class, expected_move_pct, probability,
-                horizon_days, source, is_active, taxonomy_path, updated_at
-            ) VALUES (?,?,?,?,?,?,?,?,?,?,?,'builtin',1,?,datetime('now'))""", (
-                p["id"],
-                p.get("name", ""),
-                p.get("description", ""),
-                json.dumps(p.get("triggers", [])),
-                json.dumps(p.get("keywords", [])),
-                json.dumps(p.get("historical_instances", [])),
-                json.dumps(p.get("suggested_trades", [])),
-                p.get("asset_class", "indices"),
-                p.get("expected_move_pct", 0),
-                p.get("probability", 0.5),
-                p.get("horizon_days", 30),
-                taxonomy_json,
-            ))
-        else:
-            conn.execute(
-                "UPDATE custom_patterns SET taxonomy_path=? WHERE id=? AND source='builtin'",
-                (taxonomy_json, p["id"])
-            )
-    conn.commit()
-    conn.close()
+    """No-op: built-in patterns removed in favour of Pattern Lab backtested patterns."""
+    pass
 
 
 def save_custom_pattern(pattern: Dict[str, Any]) -> str: