Align instance dashboard with hub snapshot+SSE pattern.

Background poll builds a memory snapshot; the page reads snapshot and refreshes on SSE instead of hitting heavy exchange APIs on each load.

Co-authored-by: Cursor <cursoragent@cursor.com>

lib/instance/instance_dashboard_lib.py

@@ -64,6 +64,7 @@ def _format_order_item(od: dict[str, Any]) -> dict[str, Any]:
         "title": title,
         "subtitle": subtitle,
         "symbol": sym,
+        "price_symbol": od.get("symbol") or sym,
         "direction": direction,
         "direction_label": _dir_label(direction),
         "entry": entry,
@@ -350,6 +351,38 @@ def collect_options_items(
     return out
 
 
+def enrich_order_items_with_marks(
+    items: list[dict[str, Any]],
+    *,
+    get_price: Optional[Callable[[str], Any]] = None,
+) -> list[dict[str, Any]]:
+    """后台聚合时补标记价(不打全量 fetch_positions;浮盈仍由实盘页口径负责)."""
+    if not items or not callable(get_price):
+        return items
+    out: list[dict[str, Any]] = []
+    for it in items:
+        row = dict(it)
+        sym = str(row.get("price_symbol") or row.get("symbol") or "").strip()
+        if not sym:
+            out.append(row)
+            continue
+        try:
+            px = get_price(sym)
+        except Exception:
+            px = None
+        mark = _safe_float(px)
+        if mark is None and ":" in sym:
+            try:
+                px = get_price(sym.split(":", 1)[0])
+            except Exception:
+                px = None
+            mark = _safe_float(px)
+        if mark is not None:
+            row["mark_price"] = mark
+        out.append(row)
+    return out
+
+
 def build_instance_dashboard_payload(
     conn,
     *,