feat(req-002): implement portfolio tagging and tag filters

tests/test_portfolio_comments.py

@@ -50,11 +50,20 @@ class FakeRepo:
                 setattr(portfolio, key, value)
         return portfolio
 
-    def list_portfolios(self, *, broker=None, status=None, owner_user_id=None):
+    def list_portfolios(self, *, broker=None, status=None, owner_user_id=None, include_tags=None, exclude_tags=None, match_mode=None):
         if owner_user_id is not None and self._portfolio and self._portfolio.owner_user_id != owner_user_id:
             return []
         return [self._portfolio] if self._portfolio else []
 
+    def add_tag(self, portfolio_id: str, *, tag: str):
+        raise NotImplementedError()
+
+    def list_tags(self, portfolio_id: str):
+        return []
+
+    def remove_tag(self, portfolio_id: str, *, tag: str) -> None:
+        raise NotImplementedError()
+
     def get_or_create_strategy_set(self, name: str, config: str) -> StrategySet:
         return self.strategy_set