docs: the timers, and the counts checked against the gate

ARCHITECTURE gains §14 for timers and the ring package's new shape. The test
counts were written before the review's fixes landed; they now match what the
gate actually runs.

CHANGELOG.md

@@ -111,3 +111,30 @@ Tag sections feed the release notes — see [`docs/RELEASING.md`](docs/RELEASING
   is kept rather than quietly replaced with the default: an unmounted card comes
   back. If a file you picked cannot be held onto permanently, that is disclosed
   too instead of being hidden.
+- The timers tab, for real: several timers at once, each with its own label,
+  length and sound, and a keypad that sets one in a couple of taps — with saved
+  presets you can add to and remove from as you go. A timer starts the moment
+  you press Start, so an accidental tap leaves nothing behind to delete.
+- Pause, resume, reset and "+1 min" on every timer, from the row, from the live
+  pill and from the notification — and "+1 min" on a timer that has just rung
+  starts it again with a whole minute, rather than handing back a paused timer
+  you have to press Start on.
+- A notification that counts the timer down without waking the device every
+  second: the system draws the ticking, so Clockula posts once when something
+  actually changes. It carries the same two buttons the row does, and they work
+  with the app closed.
+- A timer keeps counting across a reboot and rings when you come back — the
+  countdown is anchored on the device's uptime, so changing the system clock
+  cannot move it in either direction. Change the clock while a timer runs and
+  the notification's countdown follows the change instead of going wrong.
+- Two timers finishing together share one sound and one ten-minute window, and
+  each is stopped on its own, so you can still tell which one you have dealt
+  with. A timer left ringing goes quiet after ten minutes but stays finished, so
+  you can come back and add a minute to it — and the next timer to finish rings
+  for itself rather than inheriting that silence.
+- A timer that finishes while an alarm is ringing waits its turn instead of
+  talking over it: it is still marked finished, its notification says so, and it
+  starts sounding the moment the alarm is done.
+- Progress on each timer card is drawn by the Expressive wavy indicator, and the
+  wave itself is the state — it flattens when you pause and when the timer is
+  done.