Improve cost breakdown to show judge costs in GitHub summaries

[dcramer]

Enhance the cost summary reporting in GitHub annotations/comments to include judge costs breakdown.

Current state:

• Main annotation shows each skill's cost/duration/findings
• Per-skill comments show skill-specific details

Desired state:

• Main summary should show total judge costs and per-finding judge costs (using finding IDs)
• Per-skill annotations should show judge costs associated with that skill's findings
• Format: 'Judge [finding-ID]: cost/duration' alongside existing metrics

Scope:

• Start with GitHub Action output (annotations, PR comments)
• CLI output improvements can follow later

Depends on: Finding IDs being implemented first (gea9fxin)