feat: vertical 3-column timeline + MA regime bootstrap engine

- TimelineVertical: replace horizontal frise with Y=time vertical layout,
  3 columns (Long/Medium/Short), auto-scroll to selected date, sub-columns
  for overlapping events, today/selected-date horizontal lines
- ma_analyzer.py: detect MA50/MA200 crossovers + MA100 slope changes +
  MA20 direction swings on EUR/USD, Brent, Gold, S&P500, US10Y (5y history)
  with 5-bar confirmation, dedup, GPT-4o-mini enrichment, idempotent DB save
- POST /api/timeline/bootstrap-ma endpoint to trigger analysis
- Bootstrap MA button in Timeline page with loading state + result count

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

backend/routers/timeline.py

@@ -209,3 +209,15 @@ def bootstrap_events() -> Dict[str, Any]:
     from services.timeline_service import bootstrap_events as _bootstrap
     count = _bootstrap()
     return {"seeded": count, "status": "ok" if count > 0 else "already_seeded"}
+
+
+@router.post("/bootstrap-ma")
+async def bootstrap_ma() -> Dict[str, Any]:
+    """Detect MA ruptures on 5 key underlyings and generate historical market events via GPT."""
+    from services.ma_analyzer import bootstrap_ma_events
+    try:
+        result = await bootstrap_ma_events()
+        return {**result, "status": "ok"}
+    except Exception as e:
+        logger.error(f"[Timeline] bootstrap-ma failed: {e}")
+        raise HTTPException(500, str(e))