feat: import 👾 Issue Monster workflow

[Copilot]

Ports the Issue Monster workflow from github/gh-aw into this collection. Runs every 30 minutes, finds open issues labeled cookie, scores/prioritizes them, and assigns up to three per run to the Copilot coding agent.

New files

• workflows/issue-monster.md — the workflow itself, with these upstream-specific items stripped:
  • skip-if-check-failing (referenced lint-go, lint-js, build, test)
  • Internal shared imports (github-guard-policy.md, activation-app.md, otlp.md)
  • engine.id: pi / engine.model: copilot/gpt-5.4
• docs/issue-monster.md — documentation covering filtering logic, priority scoring table, the cookie label convention, and configuration options

README

Added Issue Monster to the Issue Farming Workflows section under Meta-Workflows.

What the workflow does

Feature	Detail
Rate-limit guard	Checks recent Copilot PR comments for rate-limit signals before assigning
Filtering	Skips assigned, has-open-PR, has-sub-issues, excluded-label, and campaign issues
Scoring	community +60 › good-first-issue +50 › security +45 › bug +40 › … + age bonus
Topic separation	Enforces the 3 selected issues are independent in scope
Sibling awareness	Sub-issues of the same parent processed one at a time, oldest first
Integrity policy	403/451 responses skipped gracefully without failing the run