added alerts collection dsql suggested

src/monitor_utils/database.py

@@ -78,11 +78,14 @@ async def add_products_to_database(
     Rewrites current fields on each upsert. Prices are recorded in a
     pastPrices array of price/date entries; a price already present in the
     array is never recorded again, so each distinct price keeps only its
-    first-seen timestamp. New products and price changes upsert an alert
-    referencing the product, deduplicated so a product holds at most one
-    unclaimed alert regardless of concurrent category or page tasks
-    detecting it; alerts write only after the product write succeeds so a
-    failed upsert cannot produce an orphaned alert.
+    first-seen timestamp. New products and never-before-recorded prices
+    upsert an alert referencing the product; a price returning to a value
+    already in pastPrices emits nothing, so per-source price oscillation
+    (member vs non-member quotes for the same SKU) alerts once per distinct
+    price instead of every run. Alerts are deduplicated so a product holds
+    at most one unclaimed alert regardless of concurrent category or page
+    tasks detecting it, and write only after the product write succeeds so
+    a failed upsert cannot produce an orphaned alert.
 
     Args:
         products: Products to upsert.
@@ -110,11 +113,11 @@ async def add_products_to_database(
         document = convert_product_to_mongo(product)
         document["_id"] = doc_id
         existing_doc = existing.get(doc_id)
-        old_price = existing_doc.get("currentPrice") if existing_doc else None
         new_price = document.get("currentPrice")
-        price_changed = new_price is not None and new_price != old_price
+        recorded_prices = extract_recorded_prices(existing_doc)
+        never_seen_price = new_price is not None and new_price not in recorded_prices
         set_on_insert = {"discoveredDate": now}
-        if existing_doc is None or price_changed:
+        if existing_doc is None or never_seen_price:
             alert = build_alert(monitor_name, document, now)
             alert_ops.append(
                 UpdateOne(
@@ -125,8 +128,7 @@ async def add_products_to_database(
             )
 
         update = {"$set": document, "$setOnInsert": set_on_insert}
-        recorded_prices = extract_recorded_prices(existing_doc)
-        if new_price is not None and new_price not in recorded_prices:
+        if never_seen_price:
             update["$push"] = {"pastPrices": {"price": new_price, "date": now}}
 
         ops.append(UpdateOne({"_id": doc_id}, update, upsert=True))