improvement: tasks feature UX fully overhauled.

.cursor/rules/lab-tasks.mdc

@@ -0,0 +1,14 @@
+---
+description: Lab Tasks tab — sort, grouping, filters, prosthesis colors
+globs: frontend/src/components/ui/lab/TasksPage.tsx,frontend/src/components/ui/lab/Task*.tsx,frontend/src/components/lab/taskListGrouping.ts,frontend/src/components/treatment/prosthesisTypeDisplay.ts,frontend/src/components/shared/catalog-type-colors.ts,backend/src/modules/tasks/**
+alwaysApply: false
+---
+
+# Lab Tasks
+
+- **Default sort:** newest `labCase.sentAt` first; `stepOrder` asc within prosthesis group (backend `buildOrderBy`).
+- **Grouping:** only when `sortBy=date`; flat list + hint for other sorts.
+- **Prosthesis colors:** `PROSTHESIS_TYPE_COLORS` + `prosthesisTypeBadgeStyleFromCatalog` — never row index.
+- **Step completed filter:** `stepCompleted` query param; groups where that step is `COMPLETED`; with `IN_PROGRESS` status shows remaining open tasks only.
+
+Full map: `.cursor/skills/lab-tasks/SKILL.md`