Fix: show completed tasks based on completedAt not dueDate

Terminal tasks (COMPLETED/CANCELLED/NA) were gated on dueDate >= cutoff,
so bulk-closed tasks with old due dates never appeared in task lists even
though they were just completed. Switch the 7-day recency check to use
completedAt instead — a task completed this week always shows regardless
of when it was due.

ondeck/src/app/(dashboard)/clients/[id]/page.tsx

@@ -75,7 +75,7 @@ export default async function ClientDetailPage({
                     {
                       AND: [
                         { status: { in: ['COMPLETED', 'CANCELLED', 'NA'] } },
-                        { dueDate: { gte: cutoff } },
+                        { completedAt: { gte: cutoff } },
                       ],
                     },
                   ],

ondeck/src/app/(dashboard)/tasks/page.tsx

@@ -36,14 +36,14 @@ export default async function TasksPage() {
           { policyGroup: { renewalDate: { gte: cutoff } } },
         ],
       },
-      // Keep ALL open tasks regardless of age; only hide ancient terminal tasks
+      // Keep ALL open tasks regardless of age; only show terminal tasks completed/closed recently
       {
         OR: [
           { status: { notIn: TERMINAL_STATUSES } },
           {
             AND: [
               { status: { in: TERMINAL_STATUSES } },
-              { dueDate: { gte: cutoff } },
+              { completedAt: { gte: cutoff } },
             ],
           },
         ],

ondeck/src/app/api/clients/[id]/tasks/route.ts

@@ -43,7 +43,7 @@ export async function GET(
           {
             AND: [
               { status: { in: ['COMPLETED', 'CANCELLED', 'NA'] } },
-              { dueDate: { gte: cutoff } },
+              { completedAt: { gte: cutoff } },
             ],
           },
         ],