Merge overlapping quality details sections in workshop-student-simulator

[Copilot]

The report issue template had two adjacent <details> blocks covering the same per-step rows, both opening with duplicate step file / overall score columns — producing near-identical sections in every generated report.

Changes

• workshop-student-simulator.md — replaces the separate "Learning quality KPIs" and "Curriculum quality metrics" <details> blocks with a single "Curriculum quality and learning KPIs" block:

  Table with: step file, overall score, active_learning score, checkpoint_quality score,
  scaffolding score, learning KPI index, lowest rubric dimension, repair priority.
  Include a row for the cohort mean at the bottom.
  

• workshop-student-simulator.lock.yml — regenerated via gh aw compile to reflect updated body hash.

• Fixes [workflow-editor] Merge overlapping quality details sections in workshop-student-simulator #2462