MC-4965

From MC-4912 roadmap (Elmar-approved 2026-06-11). ALSO AN ORCHESTRATION TEST: this ticket is deliberately left to the board-manager -> internal-Kanban -> worker pipeline; the orchestrator only monitors and gates. Worker: follow this brief exactly, commit on a branch, leave a review-required handoff. SCOPE — /tasks ops-view redesign (templates/tasks.html + minimal app.py tasks_page context; NO other templates, NO models.py): 1. Problems-first default: when problems count > 0, land on the Problems view with healthy tasks collapsed below ('N healthy tasks — show'); when 0 problems, current healthy-first behavior. Tab pills stay. 2. Single scroll container: remove the 480px inner scrollbox (max-height on .tasks-table-wrapper) so the PAGE is the only scroller; preserve the MC-4619 sticky header semantics against page scroll (position: sticky against viewport now); 'Showing X of N / Load more' bar stays reachable at the table end. 3. PRESERVE every U10/U12 behavior unchanged: cross-tab search + live counts, one status vocabulary + legend, plain-language copy, delegated tag click handler, profile column honesty, mobile card collapse at 768px. GATES (must all pass before handoff): python3 -m pytest tests/test_mc4942_u10_tasks_ux.py tests/test_mc4056_tasks_hardening.py tests/test_tasks_warning_status.py (one flex-wrap failure in mc4056 is pre-existing on master — do not chase); py_compile; sticky-header + single-scroll DOM contract test added. NOT board templates — board canary battery not required; Tessa pass happens at the orchestrator gate after landing. DO NOT: delete templates, touch /runs or task_detail, restart services, merge to master (handoff only). Expected check-in: within 2h of dispatch.