Summary

Add triage workflow for classifying untriaged ADO work items with area path,
priority, state, and tag recommendations. Includes the /ado-triage-work-items
prompt as a launcher.

Part of #774. Depends on shared infrastructure (#776).

Changes

New Files

• .github/instructions/ado/ado-backlog-triage.instructions.md
  • 2-phase workflow (Analyze → Plan/Execute)
  • 6-step analysis (discover area paths, fetch candidates, hydrate, classify, detect duplicates, record)
  • Autonomy-gated execution
  • triage-plan.md output template
• .github/prompts/ado/ado-triage-work-items.prompt.md
  • Inputs: project, areaPath, iterationPath, maxItems, autonomy, contentFormat
  • Routes through agent: ADO Backlog Manager
• collections/ado.collection.yml (triage entries)

Acceptance Criteria

• ado-backlog-triage.instructions.md created with 2-phase workflow
• ado-triage-work-items.prompt.md created and routed to ADO Backlog Manager
• contentFormat input added to triage prompt
• Collection manifest updated
• Markdown linting passes