feat: add strategy set CRUD operations (API + CLI)

tests/test_cli.py

@@ -16,6 +16,7 @@ class FakeRepo:
         self._portfolio = portfolio
         self.entries: list[LedgerEntry] = []
         self.strategy_set = StrategySet(id="set-1", name="target_value", config="{}", nick="target_value:99914b932bd3")
+        self._strategy_sets: dict[str, StrategySet] = {self.strategy_set.id: self.strategy_set}
         self.closed = False
 
     def close(self) -> None:
@@ -101,11 +102,20 @@ class FakeRepo:
 
     def get_or_create_strategy_set(self, name: str, config: str) -> StrategySet:
         self.strategy_set = StrategySet(id="set-1", name=name, config=config, nick=f"{name}:99914b932bd3")
+        self._strategy_sets[self.strategy_set.id] = self.strategy_set
         return self.strategy_set
 
     def get_strategy_set(self, id: str) -> StrategySet | None:
         return self.strategy_set if self.strategy_set.id == id else None
 
+    def list_strategy_sets(self) -> list[StrategySet]:
+        from datetime import datetime, timezone
+        return sorted(self._strategy_sets.values(), key=lambda s: s.created_at or datetime.now(timezone.utc), reverse=True)
+
+    def delete_strategy_set(self, id: str) -> None:
+        if id in self._strategy_sets:
+            del self._strategy_sets[id]
+
     def save(
         self,
         portfolio: Portfolio,