Add a new "Row 2.5" to the overview tab between the trend chart and
model/activity panels, showing two side-by-side live activity charts:
- Today: 24-bar hourly token histogram with 12h-format labels
(12a, 1a, ... 11p). Header shows total tokens consumed today.
- Last Hour: 12-bar five-minute token histogram with relative-time
labels (-55, -50, ... -5, now). Header shows tokens in the last
60 minutes.
Both charts use BarChart with theme-colored bars (Blue for today,
Accent for last hour) and adapt height in compact layouts.
Helper functions hourLabels24() and minuteLabels() generate the
X-axis label arrays.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>