[Feature]: GitHub org discovery on data ingestion page

[kiranfin]

User Story

As an Admin or PM, I want to enter a GitHub user or organization and select multiple repositories to connect.

Acceptance Criteria

• GitHub user, organization, or profile URL can be entered.
• Available repositories are displayed.
• Repositories show relevant metadata and connected status.
• Repository list supports search and pagination.
• Multiple repositories can be selected.
• Selected repositories can be connected in one action.
• Loading, empty, and error states are handled.
• The flow is restricted to Admins and PMs.

Technical Notes

• Extend the existing Data Ingestion flow.
• Use the GitHub discovery endpoint.
• Use the batch-connect or existing single-repository connect endpoint.