fix: 配额单元测试同步添加 pro 套餐

PR #1262 添加了 pro 套餐到 QUOTA_TIERS，但遗漏了
test_wave78_duplication_domain.py 中的两处断言，导致
develop CI Unit Tests 失败。

修复：
- 第 465 行：QUOTA_TIERS.keys() 断言添加 "pro"
- 第 691 行：list_tiers 断言添加 "pro"

tests/unit/test_wave78_duplication_domain.py

@@ -462,7 +462,7 @@ class TestQuotaTiers:
     def test_all_tiers_exist(self):
         from packages.domain.quota import QUOTA_TIERS
 
-        assert set(QUOTA_TIERS.keys()) == {"free", "basic", "premium"}
+        assert set(QUOTA_TIERS.keys()) == {"free", "basic", "premium", "pro"}
 
 
 # ============================================================
@@ -688,7 +688,7 @@ class TestQuotaRegistry:
 
         reg = QuotaRegistry()
         tiers = reg.list_tiers()
-        assert set(tiers) == {"free", "basic", "premium"}
+        assert set(tiers) == {"free", "basic", "premium", "pro"}
 
     def test_register_new_dimension(self):
         from packages.domain.quota import QuotaRegistry