[FEATURE]: Expand Community Files audit checklist on the Governance dashboard

### Feature and its Use Cases

### Feature Description
Currently, the **Governance** dashboard checks for basic repository licensing and some primary metrics. However, it does not audit other essential community health files required by standard open-source organizations.

This feature request proposes extending the repository audit checklist to verify and display the presence of the following files/configurations:
1. `CODE_OF_CONDUCT.md` (Code of Conduct)
2. `CONTRIBUTING.md` (Contributing Guidelines)
3. Issue Templates (checking the `.github/ISSUE_TEMPLATE/` directory)
4. Pull Request Template (`.github/pull_request_template.md` or `.github/PULL_REQUEST_TEMPLATE.md`)

### Use Cases
* **Open Source Compliance Auditing**: Helps maintainers and organization administrators quickly verify if all repositories in their portfolio conform to standard community health file requirements.
* **Contributor Onboarding Audit**: Helps developers identify which repositories need templates or contribution guidelines created, making it easier for new contributors to submit structured issues and PRs.

### Additional Context

### Suggested Implementation
* In `src/services/github.js`, add helper methods to fetch the community profile or check contents at standard paths (e.g. `https://api.github.com/repos/{owner}/{repo}/community/profile`).
* In the Governance dashboard UI (`src/pages/GovernancePage.jsx`), render a detailed checklist status grid under each repository row (e.g. using small green/red indicators or ticks/crosses for each file).

### Code of Conduct

- [x] I have joined the [Discord server](https://discord.gg/hjUhu33uAn) and will post updates there
- [x] I have searched existing issues to avoid duplicates

Start by reading the existing repository audit logic in src/services/github.js and the Governance dashboard in src/pages/GovernancePage.jsx. Check how current licensing and metrics are fetched and displayed, then use the listed GitHub community-profile or standard paths as the reference for the four checks. Done means each repository shows a status for CODE_OF_CONDUCT.md, CONTRIBUTING.md, issue templates, and pull request templates.

索引モデルが issue の本文から書いたものです。