engineer — PM Insights: Alert categories + Watch list as accordions

Date: 2026-08-29 · v2.3.1 · branch feature/insights-accordions

Built

Client (pages/Insights/index.tsx): new Section({title, count, open, onToggle, children}) accordion — a <button className={sectionHead} aria-expanded aria-controls> (chevron + title + a category-count badge) over a <div id={bodyId} className={grid} hidden={!open}>. The two sections Alert categories and Watch list are wrapped in it. Added sections state ({alerts, watch}, both default open) + toggleSection. The per-card open state (which ticket group is expanded) and the Per-PM roll-up table are untouched — Per-PM stays a plain <h2> (not requested).
Icons (components/icons/index.tsx): added ChevronIcon (right caret, shared base() pattern), rotated 90° via CSS when its section is open.
Styles (Insights.module.scss): .section / .sectionHead / .chev / .sectionTitle / .sectionCount reusing the old .h2 typographic treatment; .sectionHead[aria-expanded='true'] .chev { transform: rotate(90deg) }; and .grid[hidden] { display: none } — required, since .grid { display: grid } would otherwise beat the native hidden attribute (specificity 0,2,0 vs 0,1,0).
Version/docs: root + client package.json 2.3.0 → 2.3.1; CHANGELOG [2.3.1].

client tsc --noEmit clean (no errors outside node_modules); vite build OK (139 modules).
verifier PASS (see verifier-log.md 2026-08-29 12:07): independently reproduced tsc + build; grepped the compiled bundle to confirm ._grid…[hidden]{display:none} co-exists with ._grid…{display:grid} and wins on specificity and source order; aria-controls always resolves (body is hidden, not unmounted); slugs insights-alert-categories / insights-watch-list are distinct; per-card expand byte-for-byte unchanged → no regression; no package.json dep change.