feat: display five GLB PnL series with distinct colors

backend/app/ai/alpha_tools.py

@@ -26,10 +26,13 @@ async def search(ctx, args):
 async def pnl(ctx, args):
     data = await ctx.business.get_alpha_pnl(args.alpha_id)
     points = data.pop("points")
+    # Chart data is fetched by the UI; keep large series out of model context.
+    series = data.pop("series", [])
     return {
         **data,
         "alpha_id": args.alpha_id,
         "count": len(points),
+        "series": [{"id": item["id"], "label": item["label"]} for item in series],
         "first": points[0] if points else None,
         "last": points[-1] if points else None,
         "null_count": sum(p["value"] is None for p in points),