job status polling

Mechanism for monitoring asynchronous task progress and managing job queues via API.

Implementation Updates

site/admin/queue_api_shared.php
- Added [[concepts/stakeholder-graph-view|stakeholder_graph_view]] to $JOB_TYPES (hidden, no file upload).
- Added to defaultScheduleType() returning 'window'.
site/lab/market_radar_api.php
- Added stakeholder_graph_view to mrQueueCortexJob() allowed types.
- Added to $mrTypes in both list_mr_jobs and clear_mr_jobs.
- Integrated 3 new [[concepts/api-actions|API actions]].