Let the chart window be picked: 7, 14 or 30 days (default 7)

A 7d/14d/30d picker in the charts card sets how many days every
rolling chart covers — daily bars, sleep timeline, hour heatmap and
training consistency grid. The choice is stored per device like the
theme; headers show the current window, day labels thin out and bar
gaps tighten as the window widens, and the sleep timeline grows rows
to fit.

src/changelog.json

@@ -1,4 +1,5 @@
 [
+  { "date": "2026-07-13", "text": "Pick how many days the charts cover — 7, 14 or 30 (default 7)" },
   { "date": "2026-07-13", "text": "Much finer y-axis on the food chart" },
   { "date": "2026-07-13", "text": "The awake/asleep timer is bigger and sits first in the top bar" },
   { "date": "2026-07-13", "text": "The sleep, daily counts and food charts now cover the last 14 days instead of 7" },