Drop the big clock; keep both timers in the bar, with seconds

The asleep/awake counter rendered twice: a big card at the top of Today, and a
pill in the frozen bar that stayed invisible until the card scrolled out of
sight. That arrangement made the timer hardest to see exactly when you wanted
it — it lived on one tab in five, and hid itself whenever it was on screen.

So the card goes. Both timers sit in the frozen bar, on every tab, always
visible. That takes the standby mechanism with it, along with the rect
comparison that decided when to engage it, renderBigClockCard, and one of the
two jobs the scroll handler was doing.

Having a single place to render them is also what pays for the seconds. They
were cut to minutes last change to buy width; the month grid has since given
back about 93px by taking Today off the bar, which more than covers the 32px
the seconds cost. One row from 360px up now, wrapping only on a 320px SE and
the 280px foldable.

The pills stay at 0.9rem rather than going back to 1rem. It is tempting now
they are the only timer, but there are 6px of slack at 375px and the larger
type adds about 10, which would wrap an iPhone SE 2 and an iPhone 8.

README.md

@@ -53,9 +53,12 @@ of them, because logging has to be one tap from wherever you are.
 
 - The day bar carries up to two timers, each of which logs the boundary that
   ends what it is counting when tapped: the asleep/awake one, and — only while
-  a walk is running — the walk. They count in minutes; the big card on Today
-  keeps the seconds, and shows whichever of the two is the more immediate — the
-  walk, when there is one, since you are necessarily awake on a walk.
+  a walk is running — the walk. They are frozen at the top on every tab, and
+  they are the only place a timer appears. There used to be a big card at the
+  top of Today as well, with the pills standing by until it scrolled out of
+  sight; a timer you have to scroll to, on one tab in five, is not doing the
+  job a timer is for. Having one place to render them is also what lets them
+  carry seconds — they are the display now, not a summary of one.
 - **The day picker is a month grid of the app's own**, not the browser's. The
   native one is a sheet covering the screen, and the reason to change day is to
   see what the figures did on it — so this is a small panel under the bar, with