-- 实名即生效套餐沉默期：套餐记录字段（add-package-silence-period，技术方案 §3.1）。
-- 沉默期按每笔套餐计算，字段只建在套餐记录上，资产上不建沉默期字段。
-- 过期时 status 保持 0，由激活闸门按 silence_status 拦截。
-- 状态与时间类可空；计数类 NOT NULL DEFAULT 0；布尔 NOT NULL DEFAULT false（PostgreSQL 11+ 常量默认值不重写整表）。

ALTER TABLE tb_package_usage
    ADD COLUMN silence_status              VARCHAR(16),
    ADD COLUMN silence_start_at            TIMESTAMPTZ,
    ADD COLUMN silence_period_days         INTEGER,
    ADD COLUMN silence_deadline_at         TIMESTAMPTZ,
    ADD COLUMN silence_extended_days       INTEGER NOT NULL DEFAULT 0,
    ADD COLUMN silence_paid_extended_days  INTEGER NOT NULL DEFAULT 0,
    ADD COLUMN silence_extension_count     INTEGER NOT NULL DEFAULT 0,
    ADD COLUMN silence_free_extension_used INTEGER NOT NULL DEFAULT 0,
    ADD COLUMN silence_expired_at          TIMESTAMPTZ,
    ADD COLUMN silence_adjust_pending      BOOLEAN NOT NULL DEFAULT FALSE;

ALTER TABLE tb_package_usage
    ADD CONSTRAINT ck_package_usage_silence_status
    CHECK (silence_status IS NULL OR silence_status IN ('waiting', 'expired', 'ended'));

COMMENT ON COLUMN tb_package_usage.silence_status IS '沉默期状态：空-不适用 waiting-待实名 expired-沉默期已过期（status 保持 0） ended-截止前已实名';
COMMENT ON COLUMN tb_package_usage.silence_start_at IS '沉默期起算时间（购买支付成功时间）';
COMMENT ON COLUMN tb_package_usage.silence_period_days IS '最终沉默期天数（套餐默认值或购买时调整值）';
COMMENT ON COLUMN tb_package_usage.silence_deadline_at IS '当前沉默期截止时间（截止日 23:59:59 Asia/Shanghai，延期后更新）';
COMMENT ON COLUMN tb_package_usage.silence_extended_days IS '累计已延期天数（全部延期）';
COMMENT ON COLUMN tb_package_usage.silence_paid_extended_days IS '其中付费延期（在线与线下）累计天数，与政策累计上限比较';
COMMENT ON COLUMN tb_package_usage.silence_extension_count IS '累计延期次数';
COMMENT ON COLUMN tb_package_usage.silence_free_extension_used IS '已使用的免费延期次数';
COMMENT ON COLUMN tb_package_usage.silence_expired_at IS '最近一次沉默期过期时间';
COMMENT ON COLUMN tb_package_usage.silence_adjust_pending IS '购买时调整沉默期的审批是否进行中（进行中不过期）';