feat(pricing): 开发定价方案

packages/database/migrations/045_pricing_snapshot_guards.sql

@@ -0,0 +1,18 @@
+SET search_path TO atlas, public;
+
+ALTER TABLE product_variant_platform_listings ADD CONSTRAINT valid_pricing_requires_quote CHECK(NOT pricing_valid OR pricing_quote_id IS NOT NULL);
+
+-- 确认后只新增报价切换引用，不允许修改历史金额或规则快照。
+CREATE FUNCTION prevent_confirmed_pricing_mutation() RETURNS trigger LANGUAGE plpgsql SET search_path = atlas, public AS $$
+BEGIN
+    IF TG_TABLE_NAME='pricing_quotes' THEN
+        IF OLD.status='confirmed' THEN RAISE EXCEPTION '已确认报价不可改写' USING ERRCODE='23514'; END IF;
+    ELSE
+        IF EXISTS(SELECT 1 FROM pricing_quotes WHERE id=OLD.quote_id AND workspace_id=OLD.workspace_id AND status='confirmed') THEN
+            RAISE EXCEPTION '已确认候选快照不可改写' USING ERRCODE='23514';
+        END IF;
+    END IF;
+    RETURN NEW;
+END $$;
+CREATE TRIGGER confirmed_quote_immutable BEFORE UPDATE ON pricing_quotes FOR EACH ROW EXECUTE FUNCTION prevent_confirmed_pricing_mutation();
+CREATE TRIGGER confirmed_option_immutable BEFORE UPDATE ON pricing_quote_options FOR EACH ROW EXECUTE FUNCTION prevent_confirmed_pricing_mutation();