Good first issue: contribute an incident to the corpus

[MarouaBoud]

The corpus has 30+ sourced incidents and a live site at https://swarmproof.github.io/agent-postmortems/. Adding a new incident is a great first contribution.

How to contribute one:

1. Pick a candidate. The candidates issue (Candidate incidents for review #5) and the coverage-gaps issue (Coverage gaps vs external agent-incident sources #19) list real agent incidents we don't cover yet — or bring your own public, well-sourced case.
2. Draft it. Copy incidents/_TEMPLATE.yaml to incidents/<incident_id>.yaml (filename must equal incident_id, a YYYY-kebab-slug), fill the required core, and classify it with TAXONOMY.md.
3. Validate locally: uv run scripts/validate.py and uv run scripts/check_links.py.
4. Open a PR. The PR template carries the sourcing + neutrality checklist; CI runs every gate.

See CONTRIBUTING.md. The one rule: every incident needs a public, linkable source — no rumors, no speculation. Label a researcher PoC / near-miss as incident_type: hazard, not incident.