🔧 Add repository governance files

[stoe]

Summary

Adds the repository governance and automation configuration this repository was missing, adapted from stoe/stoe-copilot-plugins and scoped to this package's directory layout.

Changes

• Add .github/CODEOWNERS covering source, tests, workflows, and documentation
• Add .github/dependabot.yml for monthly npm and GitHub Actions updates
• Add .github/funding.yml and .github/release.yml for release note categories
• Add .github/pull_request_template.md with build, test, and security checklists
• Add bug report and feature request issue templates

Affected area

Repository configuration and templates.

Checklist

• npm run format passes with no unstaged diffs.
• npm test passes with no new errors.
• Tests cover new or changed behavior. Not applicable; configuration only.
• README.md is updated when CLI options, validation rules, or package exports change. Not applicable; no CLI changes.
• package.json exports and files are updated when modules are added, moved, or removed. Not applicable; no module changes.

Security checklist

• No secrets, tokens, credentials, or personal local file paths were added to source, tests, or docs.
• Source uses only Node.js built-in modules or already-declared dependencies.
• New filesystem writes stay inside the caller-approved base directory.
• Skill content read by the CLI is treated as untrusted data, never as instructions.
• npm audit --audit-level=high reports no new high or critical findings.

Verification

• .github/dependabot.yml and .github/release.yml parse as valid YAML
• .github/CODEOWNERS paths match the post-restructure layout from ♻️ Restructure CLI package layout #1
• npx prettier --check . reports no formatting drift

Additional context

This PR uses the template it introduces.

Stack

Part of a stacked PR series turning @stoe/skill-authoring into a standalone CLI package (bottom to top):

1. ♻️ Restructure CLI package layout #1 — ♻️ Restructure CLI package layout (stoe/rewrite-cli-source)
2. ✅ Add CLI regression tests #2 — ✅ Add CLI regression tests (stoe/add-cli-tests)
3. 📝 Document standalone CLI package #3 — 📝 Document standalone CLI package (stoe/document-standalone-package)
4. 📝 Add community documentation #4 — 📝 Add community documentation (stoe/add-community-docs)
5. 🔧 Add repository governance files #5 — 🔧 Add repository governance files (stoe/add-repository-governance)