-- Agent 主机绑定凭证：只保存 bcrypt 哈希，明文 Token 仅在签发时出现。 // Logan.Li
CREATE TABLE IF NOT EXISTS monitor_agent_credentials (
    id BIGSERIAL PRIMARY KEY,
    hostname VARCHAR(255) NOT NULL UNIQUE,
    token_prefix VARCHAR(32) NOT NULL UNIQUE,
    token_hash VARCHAR(255) NOT NULL,
    status VARCHAR(16) NOT NULL DEFAULT 'active',
    issued_by VARCHAR(128) NOT NULL DEFAULT '',
    last_used_at TIMESTAMP NULL,
    expires_at TIMESTAMP NULL,
    rotated_at TIMESTAMP NOT NULL,
    created_at TIMESTAMP NOT NULL,
    updated_at TIMESTAMP NOT NULL
);
CREATE INDEX IF NOT EXISTS idx_monitor_agent_credentials_status ON monitor_agent_credentials(status);