refactor: 清理冗余空字段

- 空 filters/filter_labels/formula 不返回
- min_amount=0 不返回
- 返回只保留有实际值的字段

pricing/pricing.py

@@ -873,16 +873,16 @@ async def get_pricing_display(ppid):
 							'filters': meaningful_filters,
 							'unit_prices': raw_tier_price
 						})
+				item = {'price_factors': price_factors_display}
+				min_amount = p.get('min_amount', 0)
+				if min_amount:
+					item['min_amount'] = min_amount
+				if filters:
+					item['filters'] = filters
+					item['filter_labels'] = filter_labels
 				if tiered_pricing:
-					price_factors_display[0]['tiered'] = tiered_pricing
-			
-			items.append({
-				'filters': filters,
-				'filter_labels': filter_labels,
-				'price_factors': price_factors_display,
-				'formula': '',
-				'min_amount': p.get('min_amount', 0)
-			})
+					item['price_factors'][0]['tiered'] = tiered_pricing
+				items.append(item)
 		else:
 			# 旧格式：formula
 			price_factors = p.get('price_factors', None)
@@ -902,12 +902,13 @@ async def get_pricing_display(ppid):
 							'unit_label': ''
 						})
 
-			items.append({
-				'filters': filters,
-				'filter_labels': filter_labels,
-				'price_factors': price_factors,
-				'formula': p.get('formula', '')
-			})
+			item = {'price_factors': price_factors}
+			if filters:
+				item['filters'] = filters
+				item['filter_labels'] = filter_labels
+			if p.get('formula'):
+				item['formula'] = p['formula']
+			items.append(item)
 
 	# 生成可读价格表
 	display_lines = [f"【{getattr(r, 'name', '')}】定价:"]