- Productive time is now a 24-hour bar chart with axes and nice tick labels
instead of a 7x24 heatmap. Model Productive field reshaped from
[7][24]int to [24]int.
- Language cards render as donut charts with a left-side legend instead of
a stacked bar. Slices beyond top-6 collapse into an "Other" row.
- Add niceTicks helper (1/2/5 * 10^k ladder, d3-style) for axis ticks.
- Legacy language_bar.go removed.
