feat: Add org-wide issue/PR templates and community health files

[Copilot]

📝 Description

Bootstraps the Magenta-Mause/.github repo with org-wide GitHub templates and community health files that automatically apply across all organization repositories.

Issue Templates (.github/ISSUE_TEMPLATE/)

• bug_report.md — reproduction steps, expected/actual behavior, environment matrix
• feature_request.md — use case, proposed solution, alternatives
• config.yml — disables blank issues; links to org discussions and security policy

PR Template (.github/pull_request_template.md)

• Change type checklist, related issue linking, manual test steps, merge readiness checklist

Community Health Files

• CONTRIBUTING.md — branch naming, Conventional Commits reference, per-language lint commands (ESLint/Prettier, Checkstyle, cargo fmt/clippy), review process, links to per-repo setup docs
• CODE_OF_CONDUCT.md — Contributor Covenant v2.1
• SECURITY.md — private vulnerability reporting via GitHub Advisories, response SLA table, supported versions per project

🔖 Type of Change

• 🐛 Bug fix (non-breaking change that fixes an issue)
• ✨ New feature (non-breaking change that adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to change)
• 📚 Documentation update
• 🔧 Refactor / code cleanup (no functional change)
• 🚀 Performance improvement
• 🔒 Security fix

🔗 Related Issues

🧪 Testing Performed

• Unit tests pass (npm test / mvn test / cargo test)
• Integration tests pass
• Manual testing performed (describe steps below)

Manual test steps:

1. Verify template chooser appears when opening a new issue in any org repo
2. Confirm PR template pre-fills on new PRs across org repos
3. Check CONTRIBUTING/CODE_OF_CONDUCT/SECURITY render correctly on GitHub

✅ Checklist

• My code follows the code style of this project (linter passes)
• I have performed a self-review of my own code
• I have commented my code where necessary (especially complex logic)
• I have updated the documentation accordingly
• My changes generate no new warnings
• I have added tests that prove my fix/feature works
• All new and existing tests pass
• Any dependent changes have been merged and published

📸 Screenshots (if applicable)

---

⚡ Quickly spin up Copilot coding agent tasks from anywhere on your macOS or Windows machine with Raycast.