移除 backend .env，暂时关闭 JWT，改为一次性登录

web/backend/internal/handlers/auth.go

@@ -54,13 +54,9 @@ func (d *Deps) Login(w http.ResponseWriter, r *http.Request) {
 		writeErr(w, http.StatusUnauthorized, "用户名或密码错误")
 		return
 	}
-	token, _, err := d.JWT.Issue(u.ID, u.Username, u.Role)
-	if err != nil {
-		writeErr(w, http.StatusInternalServerError, "issue token failed")
-		return
-	}
+	// 暂时不用 JWT，返回固定 token
 	writeJSON(w, http.StatusOK, loginResp{
-		Token: token,
+		Token: "noop",
 		User: publicUserView{
 			ID:                  u.ID,
 			Username:            u.Username,