Frontend: Operator task queue, screening, assignment, and audit view

[Abiorh001]

Parent: #29
Depends on: #50, backend locked-context work #31

Why

Flow 2 requires operators/project managers to create tasks, screen them, release ready work, assign or claim tasks, and inspect audit history. The current product has backend APIs but no real operational UI.

Roadmap Source

• docs/product_first_user_flows.md Flow 2
• docs/operations_operator_workflow.md
• docs/operations_queue_policy.md
• docs/roadmap_day_by_day_execution_plan.md Days 3-4

Scope

• Task creation/edit form against active project guide.
• Screening and release controls.
• Queue lanes by lifecycle state.
• Assignment/claim/start status views.
• Task audit event timeline.
• Visibility of locked guide/policy/payment context.

Acceptance Criteria

• Operator can create a task and see why it is blocked from screening/ready.
• Ready/claimed/in-progress/submitted/review states are scannable.
• Assignment conflicts are visible.
• Audit timeline shows actor-attributed transitions.
• UI does not allow forbidden direct status bypasses.

Contributor Fit

Core frontend task for contributors once the canonical app foundation exists.