- TaskRow: Replace tiny avatar-only display with proper assigned column
showing avatar + name (single assignee) or avatar + "N people" (multi).
Hidden on mobile, right-aligned, 96px width matching other columns.
- Load options: Chain selectinload(ProjectTaskAssignment.user) so the
user relationship is available for serialization.
- TaskAssignmentResponse: Add model_validator to resolve user_name from
eagerly loaded user relationship (same pattern as TaskCommentResponse).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>