improvement: notification feature polished. feature tabs following the same notification socket emmited data to be updated.

.cursor/rules/tab-badges.mdc

@@ -0,0 +1,16 @@
+---
+description: Sidebar tab badges (Cases/Tasks/Treatment) — activity model, tab-counts API, read cursors
+globs: backend/src/modules/notifications/**,backend/src/common/lab-case-activity.ts,frontend/src/lib/hooks/useTabBadgeCounts.ts,frontend/src/lib/tabBadgeUtils.ts,frontend/src/lib/api/notifications.ts,frontend/src/components/ui/shared/NavBadgePill.tsx,frontend/src/components/ui/shared/Sidebar.tsx
+alwaysApply: false
+---
+
+# Tab badges (Cases / Tasks / Treatment)
+
+- **Split counts (Option B):** Lab Cases = sent + clinic comments + important; Lab Tasks = completions + lab comments; Clinic Treatment = visible lab comments + completions.
+- **API:** `GET /notifications/tab-counts`; **Cases + Treatment** use per-case read + `hasUnread` on list cards; Tasks marks read on tab visit. Treatment rail uses `TreatmentLabCasesPanel` + `LabCaseTrackerCard` + activity feed.
+- **Pattern:** `useTabBadgeCounts` + `notifyTabBadgesChanged()` — same shape as `usePendingConnectionsCount`.
+- **Live:** inbox Socket.IO `notification.created` → `notifyTabBadgesChanged()` (and org pending event when relevant). **Mounted** Cases/Tasks/Treatment/Orgs pages soft-refetch lists; unmounted tabs do not. Sidebar badge counts always refetch (hook is always mounted).
+- **Orgs connections badge** stays on separate `pending-count` endpoint.
+- **Header inbox** (bell) is separate — `.cursor/skills/notifications-inbox/SKILL.md`.
+
+Full map: `.cursor/skills/tab-badges/SKILL.md`