The comparison charts (and detail-page breakdown swatches) rendered every
series in recharts' default colour instead of the per-item palette.
Root cause: `SERIES_COLORS` was defined in `components/reports/charts.tsx`,
which is a "use client" module. The report **pages are server components** and
imported the palette from it. A plain value imported from a client module into
a server component is a client-reference proxy, not the real array — so
`SERIES_COLORS[i % SERIES_COLORS.length]` was `SERIES_COLORS[NaN]` → undefined,
every line got `stroke={undefined}`, and recharts fell back to #3182bd. (The
literal `strokeWidth={2}` still applied, which is why only the colour was wrong.
It passed jsdom tests because those import the array directly, not across the
RSC boundary.)
Fix: move the palette to a dependency-free shared module `lib/report-colors.ts`
(no "use client", no server-only imports) that resolves to the real array in
both server and client graphs. `charts.tsx` and all four report pages import it
from there. It can't live in `lib/reports.ts` (that imports Prisma `db`, which
must not enter the client bundle).
Verified in a real browser: line strokes now cycle the 10-colour palette
(#2563eb, #16a34a, …) instead of a uniform #3182bd.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>