aisman

Direct session 46, Step 1: Implement issue assignment, ownership, other users toggle, resolved issues pagination:
- Issue assignment and ownership — parent issue
- Add IssueAssignedToUserId and IssueOrigSortAfter to EF model and DbContext
- Auto-assign IssueAssignedToUserId on issue creation and filter by it
- Include IssueAssignedToUserId in all DTOs and API responses
- Add resolved issues pagination endpoint (GET /api/issues/project/{id}/resolved)
- Add other users unresolved issues endpoint (GET /api/issues/project/{id}/other-users)
- Add issue reassignment endpoint (POST /api/issues/{id}/assign)
- Update status change to set IssueLastUpdated and move to resolved group
- Show owner avatar and name in issue detail meta row
- Implement 'Assign to' dialog with org member selection
- Add 'Other user's issues' toggle button and loading logic
- Implement resolved issues 'Load more' pagination on client
- Implement aim-other-user and aim-other-user-mode CSS toggle for resolved list
- Drag-drop onto other user group headers and cross-user reassignment
- Add aim-reassigned highlight class for moved issues
- Fix checkbox selection to not trigger issue detail loading
- Add SCSS styles for other-user groups, reassigned highlight, owner avatar