Remove invalid assignee from issue creation

[Copilot]

GitHub API returns 422 validation error when creating issues with assignees: ['copilot'] because the user doesn't exist or lacks repository permissions.

Changes

• Removed assignees field from createIssue() call in RepoDetail.tsx
• Updated README example to reflect current implementation

Issues continue to be labeled with 'jules' for AI agent consumption.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>fix</issue_title>
<issue_description>{
"message": "Validation Failed",
"errors": [
{
"value": [
"copilot"
],
"resource": "Issue",
"field": "assignees",
"code": "invalid"
}
],
"documentation_url": "https://docs.github.com/rest/issues/issues#create-an-issue",
"status": "422"
}
</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes fix #1

---

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[github-actions]

🚀 Netlify Deployment

Deploy URL: https://69497a2a387becf3f1d4b1e5--my-test-site3.netlify.app

Branch: copilot/fix-assignees-validation-error
Commit: aa8cfae