feat: add takeover config API endpoint

PUT /api/avatar/{avatar_id}/authorizations/takeover to update authorization
takeover settings (enabled, mode, delay_seconds) with validation.

digital-avatar-app/backend/routers/takeover.py

@@ -0,0 +1,41 @@
+"""分身接管配置 API"""
+from fastapi import APIRouter, Depends, Body
+from sqlalchemy.orm import Session
+
+from database import get_db
+from models import Authorization
+from responses import ok, fail
+
+router = APIRouter(tags=["分身接管"])
+
+
+@router.put("/avatar/{avatar_id}/authorizations/takeover")
+def update_takeover_config(
+    avatar_id: str,
+    payload: dict = Body(...),
+    db: Session = Depends(get_db),
+):
+    """更新分身接管配置"""
+    auth_id = payload.get("authorization_id")
+    if not auth_id:
+        return fail("缺少 authorization_id", 400)
+
+    auth = db.query(Authorization).filter(Authorization.id == auth_id).first()
+    if not auth:
+        return fail("授权不存在", 404)
+
+    if "takeover_enabled" in payload:
+        auth.takeover_enabled = payload["takeover_enabled"]
+    if "takeover_mode" in payload:
+        mode = payload["takeover_mode"]
+        if mode not in ("immediate", "delayed"):
+            return fail("takeover_mode 必须是 immediate 或 delayed", 400)
+        auth.takeover_mode = mode
+    if "takeover_delay_seconds" in payload:
+        delay = payload["takeover_delay_seconds"]
+        if not isinstance(delay, int) or delay < 5:
+            return fail("takeover_delay_seconds 必须 >= 5", 400)
+        auth.takeover_delay_seconds = delay
+
+    db.commit()
+    return ok(auth.to_dict())