Refine runtime data flow and UI layering

backend/domains/news.py

@@ -30,6 +30,7 @@ def ensure_news_fresh(
     *,
     ticker: str,
     target_date: str | None = None,
+    refresh_if_stale: bool = True,
 ) -> dict[str, Any]:
     """Refresh raw news incrementally when stored watermarks are stale."""
     normalized_target = str(target_date or "").strip()[:10]
@@ -44,7 +45,7 @@ def ensure_news_fresh(
     watermarks = store.get_ticker_watermarks(ticker)
     last_news_fetch = str(watermarks.get("last_news_fetch") or "").strip()[:10]
     refreshed = False
-    if not last_news_fetch or last_news_fetch < normalized_target:
+    if refresh_if_stale and (not last_news_fetch or last_news_fetch < normalized_target):
         update_ticker_incremental(
             ticker,
             end_date=normalized_target,
@@ -238,8 +239,14 @@ def get_range_explain_payload(
     end_date: str,
     article_ids: list[str] | None = None,
     limit: int = 100,
+    refresh_if_stale: bool = False,
 ) -> dict[str, Any]:
-    freshness = ensure_news_fresh(store, ticker=ticker, target_date=end_date)
+    freshness = ensure_news_fresh(
+        store,
+        ticker=ticker,
+        target_date=end_date,
+        refresh_if_stale=refresh_if_stale,
+    )
     news_rows = []
     if article_ids:
         news_rows = store.get_news_by_ids_enriched(ticker, article_ids)