[plan] Reduce Hourly CI Cleaner schedule frequency to off-peak hours

[github-actions]

Objective

Reduce the Hourly CI Cleaner workflow execution frequency from every hour to every 2-3 hours during off-peak times to cut token spend.

Context

The Copilot Token Report (referenced in discussion #7407) shows that Hourly CI Cleaner alone accounts for ~29% of Copilot token spend, despite low average cost per run. Running every hour is excessive when there may not be work to do. Reducing frequency can save ~$5-7/month.

Approach

1. Locate the Hourly CI Cleaner workflow file
2. Modify the schedule from hourly to:
   • Every 2 hours during peak hours (9 AM - 5 PM UTC)
   • Every 3 hours during off-peak hours
3. Document the rationale for the schedule change
4. Monitor token usage after implementation

Files to Modify

• Search for workflow file with schedule trigger running hourly (likely in .github/workflows/)
• Update cron expression in frontmatter

Example Schedule Change

# Before
on:
  schedule:
    - cron: '0 * * * *'  # Every hour

# After
on:
  schedule:
    - cron: '0 */2 * * *'  # Every 2 hours

Acceptance Criteria

• Workflow schedule updated to run less frequently
• Documentation explains the reduced schedule
• Token usage monitoring shows ~29% reduction in scheduled spend
• CI cleanup still functions effectively despite reduced frequency

Expected Impact

• Cuts ~29% of Copilot token spend
• Saves approximately $5-7/month
• Maintains CI cleanup effectiveness
  Related to [plan] Address DeepReport Intelligence Briefing findings (Dec 23, 2025) #7410

AI generated by Plan Command for discussion #7407