feat: 接入管理 Secret 凭据与连接刷新

internal/database/application/credentials.go

@@ -0,0 +1,58 @@
+/*
+Copyright 2026.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Package application 定义 Database 用例与适配器之间的边界。
+package application
+
+import (
+	"context"
+	"errors"
+
+	"git.ddupan.top/panxiao81/ayatori/internal/database/domain/instance"
+)
+
+var (
+	ErrCredentialsUnavailable = errors.New("management credentials unavailable")
+	ErrCredentialsInvalid     = errors.New("management credentials invalid")
+)
+
+// Credentials 只存在于应用与连接适配器内存，不进入领域对象或持久化状态。
+type Credentials struct {
+	username string
+	password string
+}
+
+func NewCredentials(username, password string) (Credentials, error) {
+	if username == "" || password == "" {
+		return Credentials{}, ErrCredentialsInvalid
+	}
+	return Credentials{username: username, password: password}, nil
+}
+
+func (c Credentials) Username() string { return c.username }
+func (c Credentials) Password() string { return c.password }
+func (c Credentials) String() string   { return "[redacted management credentials]" }
+func (c Credentials) GoString() string { return c.String() }
+
+// MarshalJSON 显式隐藏内容，避免未来字段调整意外改变日志或序列化行为。
+func (c Credentials) MarshalJSON() ([]byte, error) {
+	return []byte(`"[redacted management credentials]"`), nil
+}
+
+// CredentialReader 返回本次读取的有效值；metadata 不参与凭据相等比较。
+type CredentialReader interface {
+	Read(context.Context, instance.CredentialReference) (Credentials, error)
+}