improvement: duedate added for shipped cases. cases and tasks ui and ux updated accordingly.

backend/prisma/migrations/20260713140000_lab_case_due_date/migration.sql

@@ -0,0 +1,5 @@
+-- Expected due date for lab cases (set by clinic at send / editable until complete)
+
+ALTER TABLE "lab_cases" ADD COLUMN "dueDate" TIMESTAMP(3);
+
+CREATE INDEX "lab_cases_dueDate_idx" ON "lab_cases"("dueDate");