One visual contract for all three D3 tooltip surfaces, matching the
design reference: p-4, rounded-2xl, shadow-xl, no edge ring in light
mode. Dark mode keeps a 1px alpha-white ring since a shadow alone
disappears against dark surfaces.
- goal_projection_chart_controller drops its hand-copied class string
(it still carried the old bordered recipe — the drift this util
exists to prevent) and builds its two lines through the shared
factory: secondary date line, tabular value line.
- New content conventions exported alongside the container contract:
context line = text-xs text-secondary, values = font-medium
tabular-nums. Time-series and sankey adopt them.
- Sankey node titles now escape before .html(); user-named categories
were previously interpolated raw into the tooltip markup.
Closes#2011.
time-series and sankey each created their cursor-following tooltip with a
duplicated className literal that had already drifted apart: time-series was
missing `text-primary` and `z-50`. Move the visual contract into
app/javascript/utils/chart_tooltip.js as CHART_TOOLTIP_CLASSES and have both
controllers reference it. Each keeps its own behavioural classes (time-series
its initial `opacity-0`; both `top-0`; sankey toggles opacity via inline
style). `privacy-sensitive` stays bundled so future copies can't drop it.
Also exports a createChartTooltip factory for the raw-DOM idiom.
goal_projection_chart_controller is not in main yet (it lands with the goals
work in #1798); it migrates to the same symbol there.
