fixed

backend/app/character/service.py

@@ -0,0 +1,27 @@
+import json
+from pathlib import Path
+from typing import Any
+
+from app.character.card import DEFAULT_CARD, build_system_prompt, normalize_card
+
+CARD_PATH = Path("./data/character.json")
+
+
+class CharacterService:
+    def get_card(self) -> dict[str, Any]:
+        if CARD_PATH.is_file():
+            try:
+                raw = json.loads(CARD_PATH.read_text(encoding="utf-8"))
+                return normalize_card(raw)
+            except (json.JSONDecodeError, OSError):
+                pass
+        return normalize_card(DEFAULT_CARD)
+
+    def save_card(self, raw: dict[str, Any]) -> dict[str, Any]:
+        card = normalize_card(raw)
+        CARD_PATH.parent.mkdir(parents=True, exist_ok=True)
+        CARD_PATH.write_text(json.dumps(card, ensure_ascii=False, indent=2), encoding="utf-8")
+        return card
+
+    def get_system_prompt(self) -> str:
+        return build_system_prompt(self.get_card())