fix(ci): make CLI npm publish idempotent on duplicate release events

[jpleva91]

Summary

• The Publish @red-codes/agentguard (CLI) step in publish.yml was the only publish step without an E403-tolerance guard
• All 6 library package steps (@red-codes/core, events, matchers, policy, invariants, kernel) already use an OUTPUT=$(...) pattern to skip gracefully when a version is already published
• The CLI step ran pnpm publish naked, so any duplicate GitHub Release event caused a fatal 403 failure
• This is exactly what happened on 2026-03-29: version 2.10.2 was successfully published at 05:05:15, but a second release event at 05:06:32 caused run 23701956170 to fail

Root Cause Context (v2.10.2 Release Postmortem)

The full sequence of 5 CI failures on v2.10.2 today:

Run	Time	Workflow	Category	Status
23701803578	04:56	Release Go Kernel	build — wrong Go module agent-guard vs agentguard in handler.go	✅ fixed by #1315
23701803591	04:56	Publish to npm	build — same Go module import bug in bundled kernel	✅ fixed by #1315
23701893563	05:02	Release Go Kernel	build — same (retry)	✅ fixed by #1315
23701893570	05:02	Publish to npm	build — same (retry)	✅ fixed by #1315
23701956170	05:06	Publish to npm	E403 duplicate publish — this PR fixes	🔧 this PR

Fix

Wraps the CLI publish step in the same idempotent guard pattern used by all library packages:

OUTPUT=$(pnpm publish --provenance --access public --no-git-checks 2>&1) && echo "$OUTPUT" || {
  echo "$OUTPUT"
  if echo "$OUTPUT" | grep -q "cannot publish over the previously published"; then
    echo "::notice::@red-codes/agentguard already published at this version, skipping"
  else
    exit 1
  fi
}

Test plan

• Verify the new step pattern matches the existing library publish steps in publish.yml
• Confirm no ${{ github.event.* }} inputs are used (no injection risk)
• Next release: confirm CLI publish step tolerates a duplicate release event without failing

---

🤖 Automated triage by triage-failing-ci-agent (identity: claude-code:opus:developer) | 2026-03-29

[jpleva91]

Auto-merged by PR Merger Agent. All quality gates passed.