Create Admin Review Report

Trigger a one-off reporting agent run against any existing review (including completed ones) using a template uploaded on the spot.

Unlike the customer-facing /reports/review, this never touches the target company's Files table: the template and the generated DOCX/PDF live only in this agent run's own S3 directory ({company_id}/{agent_run_id}/...).

config_variant lets an admin try a ReviewReportConfig experiment (see backend/analyses/reporting/review.py) against a real review without risking a customer-facing run — every other trigger path is hardcoded to STABLE (ReviewReportAgent.execute).